Chapter 13: Computer Programs and Programming Language

Computer Programs and Programming Languages

• A computer program is a series of instructions that directs a computer to perform tasks.
• Created by a programmer using a programming language.

Low‐Level Languages

• Machine language is the first generation of programming languages.
• Only language the computer directly recognizes.
• Assembly language is the second generation of programming languages.
• Programmer writes instructions using  symbolic instruction codes.
• A source program contains the code to be converted to machine language.

Procedural Languages

• In a procedural language, the programmer writes instructions that tell the computer what to accomplish and how to do it.
• Third-generation language (3GL)
• A compiler translates an entire program before executing it.
• An interpreter converts and executes one code statement at a time.
• The C programming language is used to write many of today’s programs.
• COBOL (COmmon Business-Oriented Language) is designed for business applications, but easy to read because of the English-like statements.

Object-Oriented Programming Languages and Program Development Tools

• An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects.
• Other advantages include:
• objects can be reused
• programmers create applications faster
• work well in a RAD environment
• most program development tools are IDEs
• Java is an object-oriented programming language developed by Sun Microsystems.
• The Just-in-time (JIT) compiler converts the bytecode into machine-dependent code.
• The Microsoft .NET Framework allows almost any type of program to run on the Internet or an internal business network, as well as computers and mobile devices.
• Features include:
• CLR (Common Language Runtime) 
• Classes
• C++ is an extension of the C programming language.
• C# is based on C++ and was developed by Microsoft.
• F# combines the benefits of an object-oriented language with those of a functional language.
• Visual Studio is Microsoft’s suite of program development tools:
• Visual Basic is based on the BASIC programming language
• Visual C++ is based on C++
• Visual C# combines the programming elements of C++ with an easier, rapid-development environment]
• A visual programming language is a language that uses a visual or graphical interface for creating all source code.
• Borland’s Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.
• PowerBuilder is a powerful program development RAD tool.
• Best suited for Web-based, .NET, and large-scale enterprise object-oriented applications.

Other Programming Languages and Development Tools

• A 4GL (fourth-generation language) is a nonprocedural language that enables users and programmers to access data in a database.
• One popular 4GL is SQL
• Classic programming languages include:
• Ada
• ALGOL
• APL
• BASIC
• Forth
• FORTRAN
• HperTalk
• LISP
• Logo
• Modula-2
• Pascal
• PILOT
• PL/1
• Prolog
• RPG
• Smalltalk
• An application generator is a program that creates source code or machine code from a specification of the required functionality.
• Often bundled as part of a DBMS
• A macro is a series of statements that instructs an application how to complete a task.
• You usually create the macro in one of two ways:
• Record the macro with a macro recorder
• Write the macro

Web Page Development

• HTML is a special formatting language that programmers use to format documents for display on the Web.
• XHTML is a markup language that allows Web sites to be displayed more easily on mobile devices.
• XML allows Web developers to create customized tags and use predefined tags to display content appropriately on various devices.
• WML is a subset of XML and is used to design pages for microbrowsers.
• Two applications of XML are RSS 2.0 and ATOM.
• Web browsers can execute short programs to add interactive elements to Web pages.
• To send and receive information between your computer and a Web server, these programs use the CGI (common gateway interface).
• Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages:
• JavaScript
• Perl
• PHP
• Rexx
• Tcl
• VBScript
• Dynamic HTML  (DHTML) allows Web developers to include more graphical interest and interactivity.
• Cascading style sheets (CSS) contain the formats for how a particular object should be displayed.
• Ruby on Rails (RoR) provides technologies for developing object-oriented, database-driven Web sites.
• Web 2.0 allows Web sites to provide a means for users to:
• Share personal information
• Allow users to modify Web site content
• Have application software built into the site
• Most Web 2.0 sites use APIs
• An API enables programmers to interact with an environment such as a Web site or operating system.
• Web page authoring software can create sophisticated Web pages that include images, video, audio, animation, and other effects
• Dreamweaver
• Expression Web
• Flash
• SharePoint Designer

Multimedia Program Development

• Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.
• ToolBook
• Director
• Program development consists of a series of steps programmers use to build computer programs.

Step 1 – Analyze Requirements

• To initiate program development, programmer:
• Reviews the requirements
• Meets with the systems analyst and users
• Identifies input, processing, and output
• IPO chart

Step 2 – Design Solution

• Design a solution algorithm.
• In structured design, the programmer typically begins with a general design and moves toward a more detailed design.
• Programmers use a hierarchy chart to show program modules graphically.
• With object-oriented (OO) design, the programmer packages the data and the program into a single object
• Encapsulation
• The sequence control structure shows one or more actions following each other in order.
• The selection control structure tells the program which action to take, based on a certain condition.
• If then else
• Case
• The repetition control structure enables a program to perform one or more actions repeatedly as long as a certain condition is met.
• A program flowchart graphically shows the logic in a solution algorithm.
• Flowcharting software makes it easy to modify and update flowcharts
• SmartDraw
• Visio
• Pseudocode uses a condensed form of English to convey program logic.
• UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development.

Step 3 – Validate Design

• Check for logic errors using test data
• Develop various sets of test data
• Determine the expected result
• Step through the algorithm
• Compare the results
• Repeat steps for each set of test data

Step 4 – Implement Design

• Implementation of the design includes using a program development tool that assists the programmer by:
• Generating or providing some or all code
• Writing the code that translates the design into a computer program
• Creating the user interface
• Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.

Step 5 – Test Solution

• The goal of program testing is to ensure the program runs correctly and is error free.
• Errors include syntax errors and logic errors.
• Debugging the program involves removing the bugs.
• A beta is a program that has most or all of its features and functionality implemented.

Step 6 – Document Solution

• In documenting the solution, the programmer performs two activities:
• Review the program code
• Review all the documentation

CHAPTER 12: Exploring Information System Development

• System development is a set of activities used to build an information system.
• A system is a set of components that interact to achieve a common goal.
• An information system (IS) is a collection of hardware, software, data, people, and procedures that work together to produce quality information.
• System development activities are grouped into phases, collectively called the system development life cycle (SDLC).

Ongoing Activities

• Project management
• Feasibility assessment
• Documentation
• Data/information gathering

Planning

• Review project requests
• Prioritize project requests
• Allocate resources
• Form project development team

Analysis

• Conduct preliminary investigation
• Perform detailed analysis activities:
• Study current system
• Determine user requirements
• Recommend solution

Design

• Acquire hardware and software,if necessary
• Develop details of system

Implementation

• Develop programs,if necessary
• Install and test new necessry
• Train users
• Convert to new system

Operation,Support,and Security

• Perform maintenance activities
• Monitor system performance
• Assess system security 

• System development should follow three general guidelines:
• Group activities or tasks into phases
• Involve users
• Define standards
• System development should representatives from each department in which the proposed system will be used.
• Project management is the process of planning, scheduling, and then controlling the activities during system development.
• To plan and schedule a project efficiently, the project leader identifies:
• Projectscope
• Required activities
• Time estimates for each activity
• Cost estimates for each activity
• Order of activities
• Activities that can take place at the same time
• Feasibility is a measure of how suitable the development of a system will be to the organization.
• Operational feasibility
• Schedule feasibility
• Technical feasibility
• Economic feasibility
• Documentation is the collection and summarization of data and information.
• A project notebook contains all documentation for a single project.
• Users and IT professionals refer to existing documentation when working with and modifying current systems.
• During system development,members of the project team gather data and information using several techniques.
• Review documentation
• Observe
• Survey
• Interview
• JAD Sessions
• Research

Who Initiates a System Development Project

• A user may request a new or modified system
• Organizations may want to improve hardware, software, or other technology
• Situations beyond an organization's control might  require a change
• Management might mandate a change
• A user may request a new or modified information system using a request for system services or a project request.

Planning Phase

• The planning phase for a project begins when the steering committee receives a project request.
• Four major activities are performed:
• Review and approve the project requests
• Prioritize the project requests
• Allocate resources
• Form a project development team 

Analysis Phase

• The analysis phase consists of two major activities:
• Conduct a preliminary investigation
• Determines and defines the exact nature of the problem or improvement.
• Interview the user who submitted the request
• Perform detailed analysis
• Study how the current  system works
• Determine the users' wants, needs, and requirement
• Recommend a solution
• Process modeling( structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs
• Entity-relationship diagrams
• Data flow diagrams
• Project dictionary
• An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system.
• Entities are objects in the system that have data.
• A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.
• Data flow
• Processes
• Data stores
• Sources
•  The project dictionary contains all the documentation and deliverables of a project.
• Structured English is a style of writing that describes the steps in a process.
• A decision table is a table that lists a variety of conditions and the actions that correspond to each condition.
• A decision tree also shows conditions and actions, but it shows them graphically.
• The  data dictionary stores the data item's name, description, and other details about each data item.
• Object modeling combines the data with the processes that act on that data into a single unit, called an object.
• UML (Unified Modeling Language) has been adopted as a standard ntation for object modelig and development
• UML includes 13 different diagrams
• Two diagrams include:
• Use case diagram
• A use case diagram graphically shows how actors (users) interact with the information system.
• Diagrams are considered easy to understand.
• Class diagram
• A class diagram graphically shows classes and subclasses in a system.
• Each class can have one or more subclasses.
• Subclasses use inheritance methods and attributes of higher levels.
• The system proposal assesses the feasibility of each alternative solution.
• The steering committee discusses the system proposal and decides which alternative to purpyse
• Packaged software
• Custom software
• Outsourcing

Design Phase

• The design phase consists of two major activities
• Acquire hardware and software
• Develop all of the details of the new or modified information system
• To acquire the necessary hardware and software:
• Identify technical specifications
• Use research techniques such as e-zines
• Solicit vendor proposals
• RFQ,RFP. or RFI is sent to potential vendors VARs
• Test and evaluate vendor proposals
• Various techniques are used to determine the best proposal
• Make a decision
• System analyst makes recommendation to steering committee
• The next step is to develop detailed design specifications
• Sometimes called a physical design
• Database design
• Input and output design
• Program design
• Systems analyst typically develop two types of designs fr each input and output.
• A prototype (proof of concept) is a working model of the proposed system 
• Prototypes have inadequate or missing documentation
• Users tend to embrace the prototype as a final system
• Should not eliminate or replace activities
• Computer-aided software engineering (CASE) tools are designed to support one or more activities of system development.
• CASE  tools sometimes contain the following tools:
• Project repository
• Graphically
• Prototyping
• Quality assurance
• Code generator
• Housekeeping
• Many people should review the detailed design specifications.
• An inspection is a formal review of any system development deliverable
• A team examines the deliverables to identify errors

Implementation Phase

• The purpose of the implementation phase is to construct the new or modified system and then deliver it
• Develop programs
• Install and test the new system 
• Train users
• Convert to the new system
• The program development life cycle follows these steps:
• Analyze the requirements
• Design the solution
• Validate the design
• Implement the design
• Test the solution
• Document the solution
• Various tests should be performed on the new system
• Unit test 
• Verifies that each individual program or object works by itself
• System test
• Verifies that all programs in an application work together properly
• Integration test
• Verifies that an application work with other applications
• Acceptance test
•  Checks the new system to ensure that it works with actual data
• Training involves showing users exactly hoe they will use the new hardware and software in the system.
• One on one sessions
• Classroom style lectures
• Web based training
•  One or more f four conversion strategies can be used to change from the old system to the new system.

Operation, Support, and Security Phase

• The purpose of the operation, support, and security phase is to provide ongoing assistance for an information system and its users after the system is implemented.
• Perform maintenance activities
• Monitor system performance
• Assess system security
•  A computer security plan should do the following:
• Identify all information assets of an organization
• Identify all security risks that may cause an information asset loss
• For each risk, identify the safeguard that exist to detect, prevent, and recover from a loss

CHAPTER 14: ENTERPRISE COMPUTING

•       Enterprise computing involves the use of computers in networks, such as LANs and WANs, or a series of interconnected networks that encompass a variety of different operating systems, protocols, and network architectures .

•       Types of enterprises include:

•       Retail

•       Manufacturing

•       Service

•       Wholesale

•       Government

•       Educational     

•       Transportation

•       Most traditional enterprises are organized in a hierarchical manner

•       In an enterprise, users typically fall into one of four categories:

•       Executive Management

•       Middle Management

•       Operational Management

•       Nonmanagement Employees

•       Enterprise information is the information gathered in the ongoing operations of an enterprise-sized organization

•       Business intelligence

•       Business process management

•       Business process automation

•       Managers coordinate resources by performing four activities

•       Planning

•       Organizing

•       Leading

•       Controlling

Information Systems in the Enterprise

• An information system is a set of hardware, software, data, people, and procedures that work together to produce information
•  Functional units within an enterprise might include:
• Enterprise
• Accounting and Finance
• Human Resources
• Engineering or Product Development
•  Manufacturing
•  Marketing
•  Sales
• Distribution
• Customer Service
• Technology
• Accounting software manages everyday transactions
• Billing software helps the company reconcile purchases with customer payments
• Financial software helps managers budget, forecast, and analyze
• A human resources information system (HRIS) manages one or more human resources functions.
• Employee relationship management systems manage communication between employees and the business.
• Computer-aided design (CAD) uses a computer and special software to aid in engineering, drafting, and design.
• Computer-aided engineering (CAE) uses computers to test product designs.
• Computer-aided manufacturing (CAM) is the use of computers to control production equipment.
• Computer-integrated manufacturing (CIM) uses computers to integrate the many different operations of the manufacturing process.
• Material Requirements Planning (MRP) uses software to help monitor and control processes related to production.
• Manufacturing Resource Planning II (MRP II) is an extension of MRP and also includes software that helps in scheduling.
• A quality control system helps an organization maintain or improve the quality of its products or services.
• A marketing information system serves as a central repository for the tasks of a marketing department.
• Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.
• Distribution systems perform the following functions:
• Provide forecasting for inventory control
• Manage and track shipping of products
• Provide information and analysis on inventory in a warehouse
• Customer interaction management (CIM) software manages the day-to-day interactions with customers.
• The information technology (IT) department makes technology decisions for the enterprise.
• Whether to build or buy new information systems
• When a computer or information system has outlived its useful life
• Web site management programs collect data designed to help organizations make informed decisions regarding their Web presence
• General purpose information systems generally fall into one of five categories.
• Office Information System
• Transaction Processing System
• Management Information System
• Decision Support System
• Expert System
• Batch processing vs. online transaction processing.
• A Sample Expert System In Windows 7 Help and Support
• Step 1: A user enters the nature of the problem.
• Step 2: Select a suggested solution from the list presented by the expert system.
• Step 3: Expert system displays details about the solution and additional options.
• Step 4: Expert system displays detailed steps when requested.
• ·        Integrated Information Systems
  o   Customer relationship management manages information about customers, interactions with customers, past purchases, and interests
  o   Enterprise resource planning provides centralized, integrated software to help manage and coordinate ongoing activities
  o   Content management systems are information systems that combine databases, software, and procedures.
  
  

Enterprise-Wide Technologies and Methodologies

• Some technologies used in enterprises include:
• Portals
• A portal is a collection of links, content, and services presented on a Web page that are interesting for a particular job function.
• Data warehouses
• A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
• Electronic data interchange
• EDI is a set of standards that controls the transfer of business data and information among computers both within and among enterprises.
• Extranets
• An extranet is the portion of a company’s network that allows customers or suppliers of a company to access parts of an enterprise’s intranet.
• Web services
• Web services allow businesses to create products and B2B interactions over the Internet.
• In a service-oriented architecture, information systems provide services to other information systems in a well-defined manner over a network.
• Document management systems
• A document management system (DMS) allows for storage and management of a company’s documents
• Stored in a repository
• Workflow
• A workflow is a defined process that identifies the specific set of steps involved in completing a particular project or business process.
• Workflow application
• Virtual private networks
• A virtual private network (VPN) provides mobile users, vendors, and customers with a secure connection to the company network server.

Virtualization and Cloud Computing

• Virtualization is the practice of sharing or pooling computing resources.
• Server virtualization
• Provides the capability to divide a physical server logically into many virtual servers.
• Storage virtualization
• Provides the capability to create a single logical storage device from many physical storage devices.
• Cloud computing is an Internet service that provides computing needs to computer users.
• Grid computing combines many servers and/or personal computers on a network to act as one large computer.

Enterprise Hardware

• Enterprise hardware allows large organizations to manage and store information and data using devices geared for:.
• Heavy use
• Maximum availability
• Maximum efficiency
• RAID duplicates data and implements duplication in different ways.
• Network attached storage (NAS) is a server that provides storage to users and information systems attached to the network.
• A storage area network (SAN) is a high-speed network that provides storage to other servers to which it is attached.
• An enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company.
• Goal is to consolidate storage.
• A blade server packs a complete computer server on a single card (called a blade) rather than a system unit.
• The individual blades insert in a blade server chassis.
• A thin client is a small terminal-like computer that mostly relies on a server for data storage and processing.
• The processing for a thin client usually is done on a server.

High Availability, Scalability, and Interoperability

• A high-availability system continues running and performing tasks for at least 99 percent of the time.
• May include hot-swapping and redundant components.
• When a component fails, another component takes over and the system continues to function.
• Scalability is a measure of how well computer hardware, software, or an information system can grow to meet increasing performance demands.
• Interoperability is the ability for an information system to share information with other information systems within an enterprise.

Backup Procedures

•  Continuous data protection provides automatic data backup whenever data is changed in an enterprise.
• A disaster recovery plan is a written plan describing the steps a company would take to restore computer operations in the event of a disaster.
• Contains four major components.
• Emergency plan
• Backup plan
• Recovery plan
• Test plan 

·          

CHAPTER 11: MANAGE COMPUTING SECURELY,SAFELY AND ETHICALLY

Computer Security Risks

• A computer security risk is any event or action that could cause a loss of or damage to computer hardware,software,data,information,or processing capability.
• A cybercrime is an online or Internet-based illegal act
• Hackers
• Crackers
• Script Kiddlies
• Corporate Spies
• Unethical Employees
• Cyberextorrtionists
• Cyberterrorists

Internet and Network Attacks

• Information transmitted over networks has a higher degree of security risk than information kept on an organization's premises.
• An online security service is a Web site that evaluates your computer to check for Internet and e-mail vulnerabilities.
• Computer Virus
• Affects a computer negatively by altering the way the computer works
• Worm
• Copies itself repeatedly,using up resources and possibly shutting down the computer or network.
• Trojan Horse
• A malicious program that hides within or looks like a legitimate program
• Rootkit
• Program that hides in a computer and allows someone from a remote location to take full control.
• An infected computer has one or more of the following symptoms:
• Operating system runs much slower than usual
• Available memory is less than expected 
• File become corrupted
• Screen displays unusual message or image
• Music or unusual sound plays randomly
• Existing programs and files disappear
• Programs or files do not work properly
• Unknown programs or files mystereriously appear
• System properties change
• Operating system does not start up
• Operating system shuts down unexpectedly
• Users can take several precautions to protect their home and work computers and mobile devices from these malicious infections.
• A botnet is a group of compromised computers connected to a network.
• A compromised computer is known as a zombie.
• A denial of service attack (DoS attack) disrupts computer access to Internet services.
• Distributed DoS (DDoS)
• A back door is a program or set of instructions in a program that allow users to bypass security controls.
• Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate.
• A firewall is hardware and/or software that protects a network's resources from intrusion.
• Intrusion detection software
• Analyzes all network traffic
• Assesses system vulnerabilities
• Identifies any unauthorized intrusions
• Notifies network administrators of suspicious behavior patterns or system breaches.
• Honeypot
• Vulnerable computer that is set up to entice an intruder to break into it.

 Unauthorized Access and Use

• Unauthorized access is the use of a computer or network without permission.
• Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.
• Organizations take several measures to help prevent unauthorized access and use
• Acceptable use policy
• Disable file and printer sharing
• Firewalls
• Intrusion detection software
• Access controls define who can access a computer,when they can access it,and what actions they can take
• Two-phase processes called identification and authentication
• User name
• Password
• Passphrase
• CAPTCHA
• A possessed object is any item that you must carry to gain access to a computer or computer facility.
• Often are used in combination with a personal identification number(PIN)
• A biometric devices authenticates a person's identify by  translating a personal characteristic into a digital code that is compared with a digital code in a computer.
• Digital forensics is the discovery,collection,and analysis of evidence found on computers an network.
• Many areas use digital forensics
• Law enforcement
• Criminal prosecutors
• Military intelligence
• Insurance agencies
• Information security department

Hardware Theft and Vandalism

• Hardware theft is the act of stealing computer equipment.
• Hardware vandalism is the act of defacing or destroying computer equipment.
• To help reduce the of chances of theft,companies and schools use a variety of security measures
• Physical access controls
• Alarm systems
• Cables to lock equipment
• Real time location system
• Passwords,possessed objects,and biometrics

Software Theft

• Software theft occurs when someone:
• Steals software media 
• Intentionally erases programs
• Illegally copies a program
• Illegally registers and/or activates a program
• A single-user license agreement typically contains the following conditions:
• Permitted to：
• Install the software on one computer
• Make one copy of the software
• Remove the software from your computer before giving it away or selling it
• Not permitted to:
• Install the software on a network
• Give copies to friends or colleagues while continuing to use the software
• Export the software
• Rent or lease the software
• Copying,loaning,borrowing,renting,or distributing software can be a violation of copyright law.
• Some software requires product activation to function fully.

Information Theft

• Information theft occurs when someone steals personal or confidential information.
• Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.

An example of Public Key Encryption

Step 1: The sender creates a document to be e-mailed to the receiver.

Step 2: The sender uses the receiver's public key to encrypt a message.

Step 3: The receiver uses his of her private key to decrypt the message.

Step 4: The receiver can read or print the decrypted message.

• A digital signature is an encrypted code that a person,Web site,or organization attaches to an electronic message to verify the identity of the sender.
• Often used to ensure that an impostor is not participating in an Internet transaction.
• Web browsers and Web sites use encryption techniques.
• Popular security techniques include
• Digital certificates
• Transport Layer Security(TLS)
• Secure HTTP
• VPN

System Failure

• A system failure is the prolonged malfunction of a computer.
• A variety of factors can lead to system failure,including:
• Aging hardware
• Natural disasters
• Electrical power problems
• Noise,undervoltages,and overvoltages
• Errors in computer programs
• Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptable power supplies (UPS) .

Backing Up-The Ultimate Safeguard

• A backup is a duplicate of a file,program,or disk that can be used if the original is lost,damaged, or destroyed.
• to back up a file means to make a copy of it
• Offsite backups are stored in a location separated from the computer site.
• Two categories of backups:
• Full backup
• Selective backup
• Three-generation backup policy
• Grandparent
• Parent
• Child

Wireless Security

• Wireless access poses additional security risks
• About 80 percent of wireless networks have no security protection.
• War driving allows individuals to detect wireless network while driving a vehicle through the area.
• In additional to using firewalls,some safeguards improve security of wireless networks:
• A wireless access point should not broadcast an SSID.
• Change the default SSID
• Configure a WAP so that only certain devices can access it
  Use WPA or WPA2 security standards

Ethics and Society

• Computer ethics are the moral guidelines that govern the use of computers and information systems.
• Information accuracy is a concern
• Not all information on the Web is correct
• Intellectual property rights are the rights to which creators are entitled for their work.
• An IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical. 
• Green computing involves reducing the electricity and environmental waste while using a computer.
• Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them.
• Huge databases store data online.
• It is important to safeguard your information
• When you fill out a form,the merchant that receives the form usually enters it into a database.
• Many companies today allow people to specify whether they want their personal information distributed.
• A cookie is a small text file that a Web server stores on your computer.
• Web sites use cookies for a variety of reasons:
• Allow for personalization
• Store user's passwords
• Assist with online shopping
• Track how often users visit a site
• Target advertisements
• Spam is an unsolicited e-mail message or newsgroup posting.
• E-mail filtering blocks e-mail messages from designated sources.
• Anti-spam programs attempt remove spam before it reaches your inbox.
• Phishing is a scam in which a perpetrator sends an official looking e-mail message that attempts to obtain your personal and financial information.
• Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing.
• Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of trust and naivety.
• Employee monitoring involves the use of computers to observe,record,and review an employee's use of a computer.
• Content filtering is the process of restricting access to certain material on the Web.
• Many businesses use content filtering.
• Internet Content Rating Association(ICRA)
• Web filtering software restricts access to specified Web sites.

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