CHAPTER 10:MANAGING A DATABASE

Database,Data,and Information

• Database
• Collection of data organized in a manner that allows access,retrieval,and use of that data.
• Data
• Collection of unprocessed items
• Text
• Numbers
• Images
• Audio
• Video
• Information
• Processed data
• Documents
• Audio
• Images
• Video
• Database software,often called a database management system (DBMS),allows users to:
• Create a computerized database
• Add,modify,and delete data
• Sort and retrieve data
• Create forms and reports from the data
• Data integrity identifies the quality of the data.
• Garbage in,garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input.
• Valuable information should have the following characteristics:
• Accurate
• Verifiable
• Timely
• Organized
• Accessible
• Useful
• Cost-effective

The Hierarchy of Data

• Character
• A character is only byte
• Numbers,letters,space,punctuation marks,or other symbols.
• Field
• A field is a combination of one or more related characters
• Field name
• Field size
• Data type
• Common data types include:
• Text
• Numeric
• AutoNumber
• Currency
• Date
• Memo
• Yes/No
• Hyperlink
• Object
• Attachment
• Record
• A record is a group of related fields
• a primary key uniquely identifies each record.
• Data File
• A data file is a collection of related recrds.

Maintaining Data

• File maintenance refers to the procedure that keep data current
• Adding records
• Modifying records
• Deleting records
• Users add new records to a file when they obtain new data.
• Users modify a record to correct inaccurate data or update old data.
• When a record no longer is needed,a user deletes it from a file.
• Validation compares data with a set of rules or values to find out if the data is correct
• Alphabetic/Numeric check
• Range check
• Consistency check
• Completeness check
• Check digit
• Other checks

File Processing Versus Databases

• File processing system
• Each department has its own set of files
• Used for many years
• Have data redundancy
• Isolate data
• Database approach
• Programs and users share data
• Reduce data redundancy 
• Improve data integrity
• Share data
• Allows easier
• Reduces development time
• Can be more vulnerable

Database Management Systems

• A data dictionary contains data about each file in the database and each field in those files.
• A DBMS provides several tools that allow users and programs to retrieve and maintain data in the database
• Query language
• consists of simple,English-like statements that allow users to specify the data to display,print,or store.
• Query by example (QBE)
• provides a GUI to assist users with retrieving data.
• Form
• is a window on the screen that provides areas foe entering or modifying data in a database.
• Report generator
• allows users to design a report on the screen,retrieve data into the report design,and then display or print the report.

How to Use the Simple Query Wizard

Step 1: Select the fields from the Available Fields list you want to be displayed in the resulting query.

Step 2: Assign a name to the query,so that you can open it later.

Step 3: View the query results on the screen.

• A DBMS provides means to ensure that only authorized users access data at permitted times.
• Access privileges
• Principle of least privilege
• A DBMS provides a variety of techniques to restore the database to usable form in case it is damaged or destroyed
• Backup
• Log
• Recovery utility
• Continuous backup

Relational,Object-Oriented,and Multidimensional Databases

• A data model consists of rules and standard that define how the database organizes data.
• A relational database stores data in tables that consists of rows and columns.
• Each row has a primary key.
• Each columns has a unique name.
• A relationship is a link within the data.
•  Structured Query Language (SQL) is a query language that allows users to manage,update,and retrieve data.
• An object-oriented database (OODB) stores data in object.
• Examples of applications appropriate for an object-oriented database include:
• Multimedia database
• Groupware database
• Computer-aided design database
• Hypertext database
• A multidimensional database can store data in more than two dimensional of data.
• sometimes known as a hypercube
• Can consolidate data much faster than a relational database
• A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.

Web Databases

• Databases on the Web allow you to:
• Shop for products or services
• Buy or sell stocks
• Search for a job
• Make airline reservations
• Register for college classes
• Check semester grades

Database Administration

• It is important to have a carefully designed database.
• Database analysts and administrators are responsible for managing and coordinating all database activities.
• Database Analyst (DA)
• Decides on proper field placement,defines data relationship,and identifies user's access privileges.
• Database Administrator (DBA)
• Creates and maintains the data dictionary,manages security,monitors performance,and checks backup and recovery procedures
• Employees should learn how to use the data in the database effectively
• Interact with database
• Identify new data for the database
• Maintain the database

CHAPTER 8: TYPES OF STORAGE


Storage

• Storage holds data,instructions,and information for future use.
• A storage medium is the physical material on which a computer keeps data,instruction,and information.
• Capacity is the number of bytes a storage medium can hold.
• A storage device is the computer hardware that records and/or retrieves items to and from storage media.
• Reading is the process of transferring items from a storage medium into memory.
• Writing is the process of transferring items from memory to a storage medium.
• Access time measures:
• The amount of time it takes a storage device to locate an item on a storage medium.
• The time required to deliver an item from memory to the processor.

Hard Disks

• A hard disk contains one or more inflexible,circular platters that use magnetic particles to store data,instructions, and information.
• Hard disks can store data using longitudinal recording or perpendicular recording.
• Characteristics of a hard disk include:
• Capacity
• platters
• Read/Write heads
• cylinders
• sectors and tracks
• revolutions per Minute
• Transfer Rate
• Access Time
• Formatting is the process of diving the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.

How a Hard Disks Works

Step 1: The circuit board controls the movement of the head actuator and a small motor.

Step 2: A small motor spins the platters while the computer is running.

Step 3: When software requests a disk access,the read/write heads determine the current or new location of the data.

Step 4: The head actuator positions the read/write head arms over the crrect location on the platters to read or write data.

• The hard disk arms move the read/write head,which reads items and writes items in the drive.
• Location often is referred to by its cylinder.
• A head crash occurs when a read/write head touches the surface of a platter.
• Always keep a backup of your hard disk.

How Disk Cache Works

Step 1: A special-purpose chip on the hard disk, called a controller,receives a request for data,instructions,or information from the processor.

Step 2: The controller first checks disk cache for the requested item.

Step 3: If the controller does not find the requested item in disk cache,it locates the requested item on the hard disk's platters.

Step 4: The controller transfers the requested item to the processor.

• RAID (REDUNDANT ARRAY OF INDEPENDENT DISKS) is a group of two or more integrated hard disks.
• A network attached storage (NAS) device e is a server connected to a network with the sole purpose of providing storage.
• An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly.
• A removable hard disk is a hard disk that you insert and remove from a drive.
• Internal and external hard disks are available in miniature sizes(miniature hard disks).
• A disk controller consists of a special-purpose chip and electronic circuits that control the transfer of data,instructions ,and information from a disk to and from the system bus and other components of the computer.
• SATA
• EIDE
• SCSI
• SAS

Flash Memory Storage

• Flash memory chips are a type of solid state media and contain no moving parts.
• Solid state drives (SSDs) have several advantages over magnetic hard disks:
• Faster access time
• Faster transfer rates
• Generate less heat and consume less power
• Last longer
• A memory card is a removable flash memory device that you insert and remove from a slot in a computer,mobile device,or card reader/writer.
• Compact Flash(CF)
• Secure Digital (SD)
• Secure Digital High Capacity (SDHC)
• microSD
• microSDHC
• xD Picture Card
• Memory Stick
• Memory Stick Micro (M2)
• USB flash drives plug into a USB port on a computer or mobile device.
• An Express Card module is a removable device that fits in an Express Card slot.
• Developed by the PCMCIA.
• Commonly used in notebook computers.

Cloud Storage

• is an Internet service that provides storage to computer users.
• Users subscribe to cloud storage for a variety of reasons:
• Access files from any computer
• Store large files instantaneously
• Allow others to access their files
• View time-critical data and images immediately
• Store offsite backups
• Provide data center functions

Optical Discs

• An optical disc consists of a flat,round,portable disc made of metal,plastic,and lacquer that is written and read by a laser.
• Typically store software,data,digital photos,movies,and music.
• Read only vs. rewritable

How a Laser Reads Data on an Optical Disc

Step 1: A laser diode shines a light beam toward the disc.

Step 2: If light strikes a pit, it scatters.If light strikes a land, it is reflected back toward the laser diode.

Step 3: Reflected light is deflected to a light-sensing diode,which sends a digital signal of 1 to the computer.Absence of reflected light is read as a digital signal of 0.

• Optical discs commonly store items in a single track that spirals from the center of the disc to the edge.
• Track is divided into evenly sized sectors.
• A CD-ROM can be read from but not written to
• Read from a CD-ROM drive or CD-ROM player.
• A CD-R is a multisession optical disc on which users can write,but not erase.
• A CD-RW is an erasable multisession disc
• Must have a CD-RW drive
• A DVD-ROM is a high-capacity optical disc on which users can read but not write or erase
• Requires a DVD-ROM drive
• A Blu-ray Disc-ROM (BD-ROM) has a storage capacity of 100GB.
• DVD-RW,DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats.

Other Types of Storage

• Tape 
• Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information.
• A tape drive reads and writes data and information on a tape.
• Magnetic stripe cards and smart cards
• A magnetic stripe card contains a magnetic stripe that stores information.
• A smart card stores data on a thin microprocessor embedded in the card.
• Microfilm and microfiche
• store microscopic images of documents on a roll or sheet film.
• Enterprise storage
• Enterprise storage stores huge volumes of data and information for large businesses
• Uses special hardware for heavy use,maximum availability,and maximum efficiency.

Putting It All Together

• Home user
• 500 GB hard disk
• Cloud storage
• Optical disc driver
• Card reader/writer
• USB flash drive
• Small Office/Home Office user
• 1 TB hard disk
• Cloud storage
• Optical disc drive
• External hard disk for backup
• USB flash drive
• Mobile
• 250 GB hard disk
• Cloud storage
• Optical disc drive
• Card reader/writer
• Portable hard disk for backup
• USB flash drive
• Power User
• 2.5 TB hard disk
• Cloud storage
• Optical disc drive
• Portable hard disk for backup
• USB  flash drive
• Enterprise User (desktop computer)
• 1 TB hard disk
• Optical disc drive
• Smart card reader
• Tape drive
• USB flash drive
• Enterprise User (server or mainframe)
• Network storage server
• 40 TB hard disk system
• Optical disc server
• Microfilm or microfiche

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CHAPTER 7: UNDERSTANDING OUTPUT

• Output is data that has been processed into a useful form.
• An output device is any type of hardware component that conveys information to one or more people.

Display Devices

• A display devices visually conveys text, graphics, and video information.
• A monitor is packaged as a separated peripheral
• LCD monitor
• Widescreen
• Liquid crystal display (LCD) uses a liquid compound to present information on a display device.
• Active-matrix display
• Passive-matrix display
• The quality of an LCD monitor or LCD screen depends primarily on:
• Resolution
• is the number of horizontal and vertical pixels in a display device.
• A higher resolution uses a greater number of pixels.
• Response time
• Brightness
• Dot pitch
• Contrast ratio
• The graphics processing unit (GPU) controls the manipulation and display of graphics on a display device.
• LCD monitors use a digital signal and should plug into a DVI port, an HDMI port, or a Display port.
• Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150 inches.
•  Televisions also are a good output device.
• Require a convert if you are connecting your computer  to an analog television.
• Digital television (DTV) offers a crisper, higher-quality output. 
• HDTV is the most advanced form of digital television.
• A CRT monitor is a desktop monitor that contains a cathode-ray tube.
• Have a much larger footprint than do LCD monitors.

Printers

• A printer produces text and graphics on a physical medium.
• Printed information is called a hard copy, or printout.
• Landscape or portrait orientation.
• Various ways users print documents and photos
• Notebook  computer wirelessly communicates with system unit, which is connected to the printer on the home network.
• Printer prints photos in camera when camera sits in docking station.
• Printer prints image on memory card removed from camera and inserted in printer.
• Smart phone communicates with printer wirelessly.
• Digital camera communicates with printer wirelessly.
• A nonimpact printer  forms characters and graphics on a piece of paper without actually striking the paper.
• Ink-jet printers
• forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper.
• Color or black and white
• Printers with a higher dpi (dots per inch) produce a higher quality output.
• Photo printers
• produces color photo-lab-quality pictures
• Most use ink -jet technology
• PictBridge allows you to prit photos directly from a digital camera.
• Print from a memory card and preview photos on a built-in LCD screen.
• Laser printers
• High speed
• Black and white
• High quality
• Color
• Thermal printers
• generates images by pushing electrically heated pins against the heat sensitive paper.
• Thermal wax-transfer printer
• Dye-sublimation printer
• Mobile printers
• is a small,lightweight, battery-powered printer that allows a mobile user to print form a notebook computer, smart phone, or other mobile device.
• Label and postage printers
• A label printer is a small printer that prints on adhensive-type material.
• A postage printer prints postage stamps
• Postage also can printed on other types of printers.
• Plotters
• are used to produce high quality drawings.
• Large format printers
• create photo-realistic quality color prints on a larger scale.
• How a Black and White Laser Printer Works
• Step 1: After the user sends an instruction to print a document, the drum rotates as gears and rollers feed a sheet of paper into the printer.
• Step 2: A rotating mirror deflects a low powered laser beam across the surface of a drum.
• Step 3: The laser beam creates a charge that causes toner to stick to the drum.
• Step 4: As the drum continues to rotate and press against the paper, the toner transfer from the drum to the paper.
• Step 5: A set rollers uses heat and pressure to fuse the toner permanently to the paper.
• A multifunction peripheral (MFP) is a single device that prints, scans, copies, and in some cases, faxes.
• Sometimes called an all in one device.
• Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper.
• Dot-matrix printer
• produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon.
• Line printer
• prints an entire line at a time.

Speakers, Headphones, and Earbuds

• An audio output device produces music, speech, or other sounds.
• Most computer users attach speakers to their computers to:
• Generate higher quality sounds for playing games.
• Interact with multimedia presentations.
• Listen to music
• View movies
• Headphones are speakers that cover or are placed outside of the ear.
• Earbuds (also called earphones) resit inside the ear canal.
• Some speakers are specifically designed to play audio from a portable media player.
• Wireless speakers
• Voice output occurs when you hear a person's voice or when the computer talks to you through the speakers.
• Some Web sites dedicate themselves to providing voice output.
• Often works with voice input.
• VoIP uses voice output and voice input.

Other Output Devices

• are available for specific uses and applications
• Data projectors
• is a device that takes the text and images displaying on a computer screen and projects them on a larger screen.
• LCD projector
• Digital light processing (DLP) projector
• Interactive whiteboards
• is a touch sensitive device, resembling a dry-erase board, that displays the image on a connected computer screen.
• Force-feedback game controllers
• sends resistance to the device in a response to actions of the user.
• Tactile output
• provides the user with a physical response from the device

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CHAPTER 6: UNDERSTANDING INPUT

• Input is any data and instructions entered into the memory of a computer.
• Instructions can be entered into the computer in the form of programs, commands, and user responses.
• A program is a series of related instructions that tells a computer what tasks to perform and how to perform them.
• Programs respond to commands that a user issues.
• A user response is an instruction a user issues replying to a question displayed by a program.
• An input device is any hardware component that allows users to enter data and instructions into a computer.

Keyboard

• is an input device that contains keys users press to enter data and instructions into a computer.
• Most desktop computer keyboards have...
• Between 101 and 105 keys
• A numeric keypad on the right side of the keyboard
• Function keys, CTRL keys, ALT keys, and arrow keys
• WINDOWS key
• APPLICATION key
• Toggle keys
• The insertion point, also know as the cursor, is a symbol on the screen that indicates where the next character you type will appear.
• Wired keyboards
• USB port
• Wireless keyboards
• Bluetooth 
• IrDA
• An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries.
• Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace.
• Keyboards on mobile devices typically are smaller and/or have fewer keys.
• Some phones have predictive text input, which saves time when entering text using the phone's keypad.

Pointing Devices

• A pointing device is an input device that allows a user to control a pointer on the screen.
• A pointer is a small symbol on the screen whose location and shape changes as a user moves a pointing device.
• A mouse is a pointing device that fits under the palm of your hand comfortably.
• Most widely used pointing device on desktop computer.
• A mouse can be wired or wireless.
• Trackball is a stationary pointing device with a ball on its top or side.
• A touchdpad is a small, flat, rectangular pointing device that is sensitive to  pressure and motion.
• A pointing stick is a pressure-sensitive  pointing device shaped like a pencil eraser that is positioned between keys on a keyboard.
• A touch screen is a touch-sensitive display device.
• Microsoft Surface
• Touch-sensitive pads
• With pen input,you touch a stylus or digital pen on a flat surface to write,draw, or make selections.
• Video games and computer games use a game controller as the input device that directs movements and actions of on screen objects.
• Gamepads
• Joysticks and Wheels
• Light guns
• Dance pads
• Motion-sensing controllers
• A digital camera is a mobile device that allows users to take pictures and store them digitally.
• Two factors affect the quality of digital camera photos:
• Resolution
• is the number of horizontal and vertical pixels in a display device
• A pixel is the smallest element in an electronic display.
• Number of bits stored in each pixel
• Each pixel conists of one or more bits of data
• The more bits used to represent a pixel, the more colors and shades of gray that can be represented.

Voice Input

• Voice input is the process of entering input by speaking into a microphone.
• Voice recognition is the computer's capability of distinguishing spoken words.
• Audio input is the process of entering any sound into the computer
• Speech
• Music
• Sound Effects
• Music production software allows users to record, compose, mix, and edit music and sounds.

Video Input

• Video input is the process of capturing full-motion images and storing on a computer's storage medium.
• Record video on a digital video (DV) camera or use a video capture card to convert  analogs to digital.
• Connect the camera to a port on the system unit.
• Transfer video and images.
• A Web cam is a type of digital video camera that enables a user to:
• Capture video and still images
• Sends e-mail messages with video attachments
• Add live images to instant messages
• Broadcast live images over the internet
• Make video telephone calls
• A video conference is a meeting between two or more geographically separated people.

Scanners and Reading Devices

• Flatbed
• Pen or Handheld
• Sheet-fed
• Drum
• Optical character recognition (OCR) involves reading characters from ordinary documents.
• A turnaround document is a document you return to the company the creates and sends it.
• Optical mark recognition (OMR) reads hand-drawn marks such as small circles or rectangles.
• An OMR device scans the documents and matches patterns of light.
• A bar code reader, also called a bar code scanner uses laser beams to read bar codes.
• RFID (radio frequency identification) uses radio signals to communicate with a tag placed in or attached to an object.
• An RFID reader reads information on the tag via radio waves.
• RFID can track:
• Tracking times of runners in a marathon\
• Tracking location of soldiers
• Employee wardrobes
• Airline baggage
• Checking lift tickets of stickers
• Managing inventory 
• Gauging pressure and temperature of tires
• Checking out library books
• Tracking toll payments
• Magnetic stripe card readers read the magnetic strripe on the back of cards such as:
• Credit Cards\
• Entertainment cards
• Bank cards
• \Other similar cards
• MICR (maghetic ink character recognition) device read text printed with magnetized ink.
• An MICR reader converts MICR character into a form the computer can process.
• Banking industry uses MICR for check processing.
• Data collection devices obtain data directly at the location where the transaction or event takes place.
• Used in:
• Restaurants
• Grocery stores
• Factories
• Warehouses
• The outdoors

Biometric Input

• Biometric authenticates a person's identity by verifying a personal characteristic
• Fingerprint reader
• Face recognition system
• Hand geometry system
• Voice verification system
• Signature verification system 
• Iris recognition system
• Retinal scanners

Terminals

• A terminal is a computer that allows users to send data to and/or receive information from a host computer
• A POS terminal records purchases, processes payment, and update inventory.
• An automated teller machine (ATM) allows users to access their bank accounts.
• A DVD kiosk is a self-service DVD rental machine.

Suggested Input Devices by User

• Home
• Enhanced keyboard or ergonomic keyboard 
• Mouse 
• Stylus for smart phone or other mobile device
• Game controller (s)
• 30-bit 600 x 1200 ppi color scanner
• 7 MP digital camera
• Headphones that include a microphone (headset)
• Web cam
• Fingerprint reader
• Small office/ Home office
• Enhanced keyboard or ergonomic keyboard 
• Mouse
• Stylus and portable keyboard for smart phone or other mobile device, or digital pen for Tablet PC
• 36-bit 600 x 1200 ppi color scanner
• 8 MP digital camera
• Headphones that include a microphone
• Web cam
• Mobile
• Wireless mouse for notebook computer
• Touchpad or pointing stick on notebook computer
• Stylus and portable keyboard for smart phone or other mobile device, or digital pen for Table PC
• 7 or 8 MP digital camera
• Headphone that include a microphone (headset)
• Fingerprint reader for notebook computer
• Power
• Enhanced keyboard or ergonomic keyboard 
• Mouse
• Stylus and portable keyboard for smart phone or other mobile device
• Pen for graphics tablet
• 48-bit 1200 x 1200 ppi color scanner
• 9 to 12 MP digital camera
• Headphones that include a microphone (headset)
• Web cam
• Enterprise
• Enhanced keyboard or ergonomic keyboard 
• Mouse
• Stylus and portable keyboard for smart phone or other mobile device, or digital pen for Table PC
• Touch screen
• 42-bit 1200 x 1200 ppi color scanner
• 9 to 12 MP digital camera
• OCR/OMR readers, bar code readers, MICR reader, or data collection devices
• Microphone
• Video camera for video conferences
• Fingerprint reader or other biometric device

Input Devices for Physically Challenged Users

• Several input devices are available to assist physically challenged users;
• Keyguard
• Keyboards with larger keys
• On-screen keyboard
• Various pointing devices
• Head-mounted pointer
• Gesture recognition
• Computerized implant devices

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CHAPTER 5:TYPES OF UTILITY PROGRAMS AND OPERATING SYSTEMS

• System software consists of the programs that control or maintain the operations of the computer and its devices.
• An operating system (OS) is a set of programs containing instructions that work together to coordinate all the activities among computer hardware resources
• Start and shut down a computer
• Provide a user interface
• manage programs
• manage memory
• Coordinate tasks
• Configure devices
• Establish an internet connection
• Monitor performance
• Provide utilities
• Automatically update
• Control a network
• Administer security

Operating System Functions

• The process of starting or restarting a computer is called booting.
• COLD BOOT
• Turning on a computer that has been powered off completely.
• WARM BOOT
• Using the operating system to restart a computer.
• How a PC Boot
• Step 1: The power supply sends a signal to the components in the system unit.
• Step 2: The processor finds the ROM chip(s) that contains the BIOS (basic input?output system).
• Step 3: The BIOS perform the POST(power-on self test),which checks components,such as the mouse,keyboard,and adapter cards
• Step 4: The results of the POST are compared with data in a CMOS chip.
• Step 5: The BIOS may look for the system files on a USB flash drive or on an optical disc drive or may look directly on drive C (hard disk).
• Step 6: The system files and the kernel of the operating system load into memory (RAM) from storage (i.e.hard disk).
• Step 7: The operating system loads configuration information,may request user information,starts several background processes,and displays the desktop on the screen.
• A boot drive is the drive from which your computer starts
• You can boot from a boot disk.
• A recovery disk contains a few system files that will start the computer.
• An operating system includes various shut down options
• Sleep mode saves any open documents and programs to RAM, turns off all unneeded functions,and then places the computer in a low-power state.
• Hibernate saves any open documents and programs to hard disk before removing power from the computer.
• A user interface controls how you enter data and instructions and how information is displayed on the screen.
• With a graphical user interface (GUI), you interact with menus and visual images.
• With a command-line interface,a user uses the keyboard to enter data and instructions.
• How an operating system handles programs directly affects your productivity
• Single user and multiuser
• Single tasking and multitasking
• Foreground and background
• Preemptive multitasking
• Multiprocessing
• Memory management optimizes the use of RAM.
• Virtual memory is a portion of a storage medium functioning as additional RAM.
• The operating system determines the order in which tasks are processed
• A driver is a small program that tells the operating system how to communicate with a specific device.
• Plug and Play automatically configures new devices as you install them.
• Operating systems typically provide a means to establish internet connections.
• A performance monitor is a program that assesses and reports information about various computer resources and devices.
• Operating systems often provide users with the capability of; 
• Managing files
• Searching for files
• Viewing images
• Securing a computer
• Uninstalling programs
• Cleaning up disks
• Defragmenting disks
• Diagnosing problems
• Backing up files and disks
• Setting up screen savers
• Automatic update automatically provides updates to the program
• Some operating systems are designed to work with a server on a network.
• A server operating system organizes and coordinates how multiple users access and share resources on a network.
• A network administrator uses the server operating system to:
• Add and remove users, computers, and other devices
• Install software and administer network security
• Each user has a user account
• A user name, or user ID, identifies a specific user
• A password is a private combination of character associated with the user name
• Types of Operating Systems
• Stand-alone
• DOS
• Early Windows versions(Windows 3.x, Windows 95,Windows NT Workstation, Windows 98, Windows 2000 Professional, Windows Millennium Edition, Windows XP, Windows Vista) 
• Windows 7
• Mac OS X
• UNIX
• Linux
• Server
• Early Windows Server versions (Windows NT Server, Windows 2000 Server, Windows Server 2003)
• Windows Server 2008
• UNIX
• Linux
• Solaris
• NetWare
• Embedded
• An embedded operating system resides on a ROM chip on a mobile device or consumer electronic device

• Windows Embedded CE
• Windows Phone 7
• Palm OS
• iPhone OS
• BlackBerry
• Google Android
• Embedded Linux
• Symbian OS

Stand-Alone Operating Systems

• A stand-alone operating system is a complete operating system that works on a desktop computer, notebook computer, or mobile computing device
• Windows 7
• is Microsoft's fastest, most efficient operating system to date and is available in multiple editions:
• Windows 7
• Windows 7 Home Premium
• Windows 7 Ultimate
• Windows 7 Professional
• provides programs such as:
• Windows Firewall
• Windows DVD Maker
• Windows Media Player
• Desktop Gadget Gallery
• Mac OS X
• The Macintosh operating system has set the standard for operating system ease of use
• Latest version is Mac OS X
• UNIX
• is a multitasking operating system developed in the early 1970s.
• Linux
• is an open-source, popular, multitasking UNIX-type operating system

Server Operating Systems

• Windows Server 2008
• is an upgrade to Windows Server 2003
• Part of the Windows Server 2008 family
• Multiple editions
• Most editions include Hyper-V,a virtualization technology
• Virtualization is the practice of sharing or pooling computing resources
• UNIX
• Linux
• Solaris
• NetWare

Utility Programs

• is a type of system software that allows a user to perform maintenance-type tasks
• A file manager is a utility that performs functions related to file management
• Displaying a list of files
• Organizing files in folders
• Copying,renaming,deleting,moving,and sorting files and folders
• Creating shortcuts
• A search utility is a program that attempts to locate a file on your computer based on criteria you specify.
• An image viewer allows users to display,copy, and print the contents of a graphics file.
• An uninstaller removes a program, as well as any associated entries in the system files.
• A disk cleanup utility searches for and removes unnecessary files
• Download program files
• Temporary internet files
• Deleted files
• Unused program files
• A disk defragmenter reorganizes the files and unused space on a computer's hard disk so that the operating system accesses data more quickly and programs run faster
• Defragmenting
• A backup utility allows users to copy files to another storage medium.
• A restore utility reverses the process and returns backed up files to their original form.
• A screen saver causes a display device's screen to show a moving image or blank screen if no activity occurs for a specified time.
• A personal firewall detects and protects a personal computer from unauthorized instrusions.
• A virus describes a potentially damaging computer program that affects a computer negatively.
• A worm copies itself repeatedly in memory or over a network.
• A Trojan horse hides within or looks like a legitimate program.
• An antivirus program protects a computer against viruses.
• Spyware is a program placed on a computer without the user's knowledge that secretly collects information about the user.
• A spyware remover detects and deletes spyware and other similar programs.
• Adware displays on online advertisement in a banner or pop-up window.
• An adware remover is a program that detects and deletes adware.
• Filters are programs that remove or block certain items from being displayed
• Web filtering software
• Anti-spam programs
• Phishing filters
• Pop-up blockers
• A  file compression utility shrinks the size of a file(s)
• Compressing files frees up room on the storage media
• Two types of compression
• Lossy
• Lossless
• Compressed files sometimes are called zipped files
• can be uncompressed
• A media player allows you to view images and animation, listen to audio,and watch video files on your computer.
• Disc burning software writes text,graphics, audio,and video files on a recordable or rewritable optical disc.
• A personal computer maintenance utility identifies and fixes operating system problems,detects and repairs disk problems, and includes the capability of improving a computer's performance.

System Unit Components

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Chapter 4: System Unit Components


The System Unit

• is a case that contains electronic components of the computer used to process data
• The inside of the system unit on a desktop personal computer includes:
• Drive bay (s)
• Power supply 
• Sound card
• Video card
• Processor
• Memory
• The motherboard is the main circuit board of the system unit
• A computer chip contains integrated circuits

Processor

• also called central processing unit (CPU), interprets and carries out the basic instructions that operate a computer
• contain a control unit and arithmetic logic unit (ALU)
• Multi-core processor
• Dual-core processor
• Quad-core processor
• The control unit is the component of the processor that directs and coordinates most of the operations in the computer.
• The arithmetic logic unit (ALU) performs arithmetic, comparison,and other operations.
• For every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle
• Step 1: The control unit fetches the math problem's instructions and data from memory.
• Step 2: The control unit decodes the math problem's instructions and sends the instructions and data to the ALU.
• The ALU performs calculations on the data.
• Step 4: The results of the math problem are stored in memory.
• Most current personal computers support pipelining.
• Processor begins fetching a second instruction before it completes the machine cycle for the first instruction.
• The processor contains registers,that temporarily hold data and instructions
• The system clock controls the timing of all computer operations
• The pace f the system clock is called the clock speed, and is measured in gigahertz (GHz)
• The leading manufacturers of personal computer processor chips are lntel and AMD.
• Determine how you plan to use a new computer before selecting a processor.
• A processor chip generates heat that could cause the chip to burn up.
• Require additional cooling
• Heat sinks
• Liquid cooling
• Liquid cooling technology
• Parallel processing uses multiple processrs simultaneously to execute a single program or task
• Massively parallel processing involves hundreds or thousands of the processors.

Data  Representation

• Analog signals are continuous and vary in strength and quality.
• Digital signals are in one of two states:on or off.
• Most computers are digital.
• The binary system uses two unique digits (0 and 1）
• Bits and bytes
• A computer circuit represents the 0 or the 1 electronically by the presence or absence of an electrical charge.
• Eight bits grouped together as a unit are called a byte. A byte represents a single character in the computer.
• ASCII (American Standard Code for Information Interchange) is the most widely used coding scheme to represent data.

How a Letter Is Converted to Binary Form and Back

Step 1: A user presses the capital letter T (SHIFT+T keys)on the keyboard,which in turn creates a special code,called a scan code,for the capital letter T.

Step 2: The scan code for the capital letter T is sent to the system unit.

Step 3: The system unit converts the scan code for the capital letter T to its ASCII binary code (01010100) and stores it in memory for processing.

Step 4: After processing, the binary code for the capital letter T is converted to an image and displayed on the output device.

Memory

• consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results pf processing the data.
• Stores three basic categories of items:
• The operating system and other system software
• Application programs
• Data being processed and the resulting information
• Each location in memory has an address
• Memory size is measured in kilobytes (KB or K), megabytes(MB),gigabytes(GB),or terabytes(TB).
• The system unit contains two types of memory:
• Volatile memory
• Loses its contents when power is turned off
• Example includes RAM
• Nonvolatile memory
• Does not lose contents when power is removed
• Examples include ROM,flash memory,and CMOS

How Program Instructions Transfer in and out of RAM

Step 1: When you start the computer,certain operating system files are loaded into RAM  from the hard disk.The operating system displays the user interface on the screen.

Step 2: When you start a Web browser,the program's instructions are loaded into RAM from the hard disk. The Web browser and certain operating system instructions are in RAM. The Web browser window appears on the screen.

Step 3: When you start a paint program,the program's instructions are loaded into RAM from the hard disk.The paint program,along with Web browser and certain operating system instructions,are in RAM.the paint program window appears on the screen.

Step 4: When you quite a program,such as the Web browser,its program instructions are removed from RAM.The Web browser no longer is displayed on the screen.

• Three basic types of RAM chips exist:
• Dynamic RAM (DRAM)
• Static RAM (SRAM)
• Magnetoresistive RAM (MRAM)
• RAM chips usually reside on a memory module and are inserted into memory slots.
• The amount  of  RAM necessary in a computer often depends on the types of software you plan to use
• 2 GB or less
• Home and business users ,managing personal finances;using standard application software such as word processing;using educational or entertainment optical discs;communicating with others on the Web.
• 2 GB to 8 GB
• Users requiring more advanced multimedia capabilities;running number-intensive accounting, financial, or spreadsheet programs;using voice recognition;working with videos,music, and digital imaging;creating Web sites; participating in video conferences;playing internet games.
• 8 GB and up
• Power users creating professional Web sites;running sophisticated CAD, 3-D design, or other graphics-intensive software.
• Memory cache speeds the processes of the computer because it stores frequently used instructions and data.
• Read-only memory (ROM) refers to memory chips storing permanent data and instructions.
• A PROM (programmable read -only memory)chip is a blank ROM chip that can be written to permanently.
• Flash memory can be erased electronically and rewritten.
• CMOS technology provides high  speeds and consumes little power.
• Access time is the amount of time it takes the processor to read from memory.
• Measured in nanoseconds

Expansion Slots and Adapter Cards

• An expansion slot is a socket on the motherboard that can hold an adapter card.
• An adapter card enhances functions of a component of the system unit and/or provides connections to peripherals
• Sound card and video card
• With Plug and Play, the computer automatically can configure adapter cards and other peripherals as you install them.
• Removable flash memory includes:
• Memory cards,USB flash drives,and PC Cards/Express Card modules

Ports and Connectors

• A port is the point which a peripheral attaches to or communicates with a system unit (sometimes referred to as a jack)
• A connector joins a cable to a port.
• On a notebook computer, the ports are on the back, front,and/or sides.
• A USB port can connect up to 127 different peripherals together with a single connector.
• You can attach multiple peripherals using a single USB port with a USB hub.
• Other types of ports include:
• Firewire port
• Bluetooth port
• SCSI port
• ESATA port
• lrDA port
• Serial port
• MIDI port
• A Bluetooth wireless port adapter converts a USB port into  a Bluetooth port.
• A smart phone might communicate with a notebook computer using an lrDA port.
• A port replicator is an external device that provides connections to peripherals through ports built into the device.
• A docking station is an external device that attaches to a mobile computer or device.

Buses

• A bus allows the various devices both inside and attached to the system unit to communicate with each other
• Data bus
• Address bus
• Word size is the number of bits the processor can interpret and execute at a given time.
• Expansion slots connect to expansion buses
• Common types of expansion buses include:
• PCI bus
• PCI Express bus
• Accelerated Graphics Port
• USB and Firewire bus
• PC Card bus

Bays

• A bay is an opening inside the system unit in which you can install additional equipment
• A drive bay typically holds disk drives.

Power Supply

• The power supply converts the wall outlet AC power into DC power.
• Some external peripherals have an AC adapter,which is an external power supply.

Putting It All Together

• Home
• Intel Core i5
• Intel Core 2 i3
• AMD Athlon II
• AMD Sempron
• Minimum RAM:2 GB
• Small office/Home office
• Intel Core i7
• Intel Core i7 Extreme
• AMD Phenom II
• AMD Athlon II
• Minimum RAM : 4 GB
• Mobile
• INtel Core i7 Extreme
• Intel Core i7
• AMD Phenom II
• AMD Turion II
• Minimum RAM: 2 GB
• Power
• Intel Xeon 
• Intel Itanium 
• AMD Opteron
• Minimum RAM:8 GB
• Enterprise
• Intel Core i7
• Intel Core i7 Extreme
• AMD Phenom II
• AMD Athlon II
• Minimum RAM: 4 GB

Keeping Your Computer or Mobile Device Clean

• Clean your computer or mobile device once or twice a year
• Turn off and unplug your computer or mobile device before cleaning it.
• Use compressed air to blow away dust.
• Use an antistatic wipe to clean the exterior of the case and a cleaning solution and soft cloth to clean the screen.

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Chapter 3: Software for System

Application Software

• consists of programs designed to make users more productive and/or assist with personal tasks
• To make business activities more efficient
• To assist with graphics and multimedia projects
• To support home, personal, and educational tasks
• To facilitate communications
• Available in a variety of forms:
• Packaged software
• Custom software
• Web application
• Open source software
• Shareware 
• Freeware
• Public-domain software
• System software serves as the interface between the user, the application software,and the computer's hardware
• Utility programs

Business Software

• is application software that assists people while performing business activities
• Word Processing
• Word processing software allows users to create and manipulate documents
• Developing a document
• CREATE A DOCUMENT
• enter text numbers
• insert images
• perform other tasks
• EDIT A DOCUMENT
• make changess to existing content
• inserting,delating,cutting,copying,and pasting
• FORMAT A DOCUMENT
• change appearance-font,font size
• Spreadsheet
• allows users to organize data in rows columns and perform calulations
• Charting depicts data in a spreadsheet in graphical form
• Database
• is a collection of data organized in a manner that allows access,retrieval,and use of that data
• allows users to create,access,and manage a database
• Presentation
• allows users to create visual aids for presentations to communiate ideas,message,and other information to a group.
• Note Taking
• is application software that enables users to enter typed text,handwritten comments,drawings,or sketches anywhere on a page.
• Personal Information Manager
• A personal information manager(PIM) is application software that includes
• Appointment calendar
• Address book
• Notepad
• Business Software for Phones
• Scaled down versions of software are available to work with smart phones and other mobile devices.
• Business Software Suites
• is a collection of individual programs available together as a unit
• Project Management
• allows a user to plan,schedule,track,and analyze the events,resources,and costs of a project
• Accounting
• helps companies record and report their financial transactions
• Document Management
• provides a means for sharing,distributing,and searching through documents y converting them into a format that can be viewed bu any user.
• Enterprise Computing Software
• Enterprise typically require special computing solutions for various functional units
• Human resources
• Accounting
• Engineering
• Manufacturing
• Marketing
• Sales
• Distribution
• Customer service
• Information technology

Graphics and Multimedia Software

• Computer-aided design(CAD) software
• Desktop publishing software
• Paint/Image editing software
• Professional photo editing software
• Video and audio editing software
• Multimedia authoring software
• Web page authoring software helps users of all skill levels create Web pages that include multimedia and interactive content.

Software for Home, Persoanl, and Educational Use

• Personal finance software
• Legal software
• Tax preparation software
• Personal DTP software
• Personal paint/image editing software
• Personal photo editing software
• Clip art/image gallery
• Video and audio editing software
• Home design/landscaping software
• Travel and mapping software
• Reference software
• Educational software
• Entertainment software

Web Applications

• is a Web site that allows users to access and interact with software from any computer or device that is connected to the internet.

Application Software for Communications

• Web Browser
• E-Mail
• Instant Messaging
• Chat Room
• Text,Picture,Video Messaging
• RSS Aggregator
• Blogging 
• Newsgroup/Message Board
• FTP
• VolP
• Video Conferencing

Learning Tools for Application Software

• Online Help is the electronic equivalent of a user manual.
• You can ask a question or access the Help topics in subject or alphabetical order.
• Web-based Help provides updates and more comprehensive resources to respond to technical issues about software.
• Web-based training is a type of  CBT that uses internet technology and consists of application software on the Web.
• Distance learning (DL) is the delivery of education at one location while the learning takes place at other locations.

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Chapter 2: FUNDAMENTALS OF THE WORLD WIDE WEB AND INTERNET

• The INTERNET is a worldwide collection of networks that links millions of businesses,government agencies, educational institutions, and individuals.

Evolution of the Internet

• The internet originated as APPANET in September 1969 and had two main goals:
• allow scientists at different physical location to share information and work together
• function even if part of the network were disabled  or destroyed by a disaster
• Each organization is responsible only for maintaining its own network
• The World Wide Web Consortium (W3C) oversees research and sets guidelines and standards
• Internet 2 connects more than 200 universities and 115 companies via a high-speed private network
• Many home and small business users connect to yhe internet via high-speed broadband internet service
• An access provider is a business that provides individuals and organization access to the internet free or for a fee

How a Home User's Data and Information Might Travel the Internet Using a Cable Modern Connection

Step 1: You initiate an action to request data or information from the internet.For example,you request to display a Web page on your computer screen.

Step 2: A cable modern transfers the computer's digital signals to the cable television line in your house.

Step 3: Your request (digital signals) travels through cable television lines to a central cable system, which s shared by up to 500 homes in a neighborhood.\

Step 4: The central cable system sends your request over high-speed fiber-optic lines to the cable operator, who often also is the ISP.

Step 5: The ISP routes your request through the internet backbone to the destination server (in this example, the server that contains the requested Web site)

Step 6: The server retrieves the requested Web page and sends it back through the internet backbone to your computer.

• An IP  address is a number that uniquely identifies each computer or device connected to the internet
• A domain name is the text version of an IP address
• Top-level domain (TLD)
• A DNS server translates the domain name into its associated IP address

The World Wide Web

• The World Wide Web,or Web, consists of a worldwide collection of electronic documents (Web pages).
• A Web site is a collection of related Web pages and associated items.
• A Web server is a computer that delivers requested Web pages to your computer.
• Web 2.0 refers to Web sites that provide a means for users to interact.
• A Web browser, or browser, allows users to access Web pages and Web 2.0 programs
• Internet Explorer
• Firefox
• Opera
• Safari
• Google Chrome

How a Web Browser Display a Home Page

Step 1: Start the Web browser software by clicking the Web browser icon on the taskbar or typing the Web browser name in the search box on the Start menu.

Step 2: Behind the scenes, the Web browser looks up its home page setting. For illustration purposes only, the screen on the right shows the home page setting is msn.com.

Step 3: The Web browser communicates with a server maintained by your internet access provider. The server translates the domain name of the home page to an IP address and then sends the IP address to your computer.

Step 4: The Web browser users the IP address to contact the Web server associated with the home page and then requests the home page from the server.The Web server sends the home page to the Web browser,which formats the page for display on your screen. 

• A home pages is the first page that a Web site displays
• Web pages provide links to other related Web pages
• Surfing the Web
• Downloading is the process of receiving information
• Some Web pages are designed specifically for microbrowsers
• A Web page has a unique address called a URL or Web address
• Tabbed browsing allows you to open and view multiple Web pages in a single Web browser window.
• Two types of search tools are search engines and subject directories:
• SEARCH ENGINES-finds information related to a specific topic
• SUBJECT DIRECTORY-classifies Web pages in an organized set of categories
• A search engine is helpful in locating items such as:
• Images
• Videos
• Audio
• Publications
• Maps
• People or Businesses
• Blogs
• Some Web browsers contain an Instant Search box eliminate the steps of displaying the search engine's Web page prior to entering the search text.
• There are thirteen types of Web sites:
• Portal
• News
• Informational
• Business/ Marketing
• Blog
• Wiki
• Online Social Network
• Educational
• Entertainment
• Advocacy
• Web Application 
• Content Aggregator
• Personal
• Information presented on the Web must be evaluated for accuracy
• No one oversees the content of Web pages
• Multimedia refers to any application that combines text with:
• Graphics
• is a digital representation of non text information
• Graphic formats include BMP,GIF,PNG,and TIFF
• A thumbnail is a small version of a larger graphic

• Animation
• is the appearance of motion created by displaying a series of still images in sequence
• Audio
• includes music,speech,or any other sound 
• Compressedto reduce file size
• You listen to audio on your computer using a player
• Streaming is the process of transferring data in a continuous and even flow
• ACC-advanced audio coding
• AIFF-audio interchange file format
• ASF-advanced streaming(or systems) format(part of windows media framework)
• MP3-moving pictures experts group audio layer 3(MPEG-3)
• Ogg-free,unpatented audio and video format
• WAV-windows waveform
• WMA-windows media audio(part of Windows Media framework)
• RA-real audio sound file (supported by Real Player)
• OT-quick time audio,video,or 3-D animation

How to Purchase and Download Music Using iTunes

Step 1: Display the iTunes program on the screen,Search for, select ,and pay for the music you want to purchase from the iTunes Music Store,which is integrated in the iTunes program.

Step 2: Download the music from the iTunes Music Store server to your computer's hard disk.

Step 3: Listen to the music from your computer's hard disk.Download music from your computer's hard disk to a portable media player. Listen to the music through earbuds attached to the portable media player.

• Video 
• consists of images displayed in motion.
• Virtual Reality
• is the use of computers to simulate a real or imagined environment that appears as a three-dimensional space.
• A plug-in is a program that extends the capability of a Web browser.
• Web publishing is the development and maintenance of Web pages
• Plan a Web site
• Analyze and design a Web site
• Create a Web site
• Deploy a Web site
• Maintain a Web site

E-Commerce

• E-commerce is a business transaction that occurs over an electronic network.
• M-commerce identifies e-commerce that takes place using mobile devices.

An Example of E-Retail

Step 1: The customer displays the e-retailer's electronic storefront.

Step 2: The customer collects purchases in an electronic shopping cart.

Step 3: The customer enters payment information on a secure Web site.The e-retailer sends financial information to a bank.

Step 4: The bank performs security checks and sends authorization back to the e-retailer.

Step 5: The e-retailer's Web server sends confirmation to the 

customer,processes the order,and then sends it to the fulfillment center.

Step 6: The fulfillment center packages the order,prepares it for shipment,and then sends a report to the server where records are updated.

Step 7: While the order travels to the customer, shipping information is posted on the Web.

Step 8: The order is delivered to the customer, who may be required to sign a handheld computer or document to acknowledge receipt.

Other Internet Services

• E-mail is the transmission of messages and files via a computer network.
• An e-mail program allows you to create,send,receive,forward ,store,print,and delete e-mail messages.

How an E-Mail May Travel from a Sender to a Receiver

Step 1: Using an e-mail program, you create and send a message.

Step 2: You e-mail program contacts software on you service provider's outgoing mail server.

Step 3: Software on the outgoing mail server determines the best route for the data and sends the  message,which travels along internet routers to the recipient's incoming mail server.

Step 4: When the recipient uses an e-mail program to check for e-mail messages,the message transfers from the incoming mail server to the recipient's computer.

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Computer Software

• Software also called a program tells the computer what tasks to perform and how to perform them.
• Installing is the process of setting up software to work with the computer, printer, and other hardware.
• A programmer develops software or writes the instructions that direct the computer to process data into information.

Categories of Computer

• Personal computer-Fits o desk
• Mobile computer&mobile devices-Fits on lap or in hand
• Game consoles-small box or handheld device
• servers-small cabinet
• Mainframes-Partial room to a full room of equipment
• Supercomputer-Full room of equipment
• Embedded computers-Mainiature

Elements of an Information System

• Hardware
• Software
• Data
• People
• Procedures

Examples of Computer Usage

• Home user
• Small office/Home Office User
• Mobile User
• Power User
• Enterprise User

Computer Applications in Society

• Education
• Finance
• Government
• Health care
• Science
• Publishing
• Travel
• Manufacturing

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• A computer is an electronic device,operating under the control of instructions stored in its own memory.
• A computer contains many electric, electronic,and mechanical components known as hardware.
• Input device
• Output device
• System unit
• Storage device
• Communication device

• Advantages of using computer
• Speed
• Reliability
• Consistency
• Storage
• Communications
• Disadvantages of using computer
• Health risk
• Violation of privacy
• Public safety
• Impact on labor force
• Impact of Environment

Networks and the Internet

• A network is a collection of computers and devices connected together,often wirelessly,via communications devices and transmission media.
• The internet is a worldwide collection of networks that connects millions of businesses,government agencies,educational institutions and individuals.
• The reason of use the internet:
• Communicate
• Research and access information
• Shop
• Bank and invest 
• Online trading
• Entertainment
• Download videos
• Share information
• Web application
• A social networking web site encourages members to share their interests,ideas, stories, photos, music, and videos with other registered users.