Tuesday 18 October 2016

Chapter 14: Enterprise Computing

What is  Enterprise Computing? Finally last chapter

  1. 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 .
  2. Types of enterprises include:
    • Retail
    • Manufacturing
    • Service
    • Wholesale
    • Government
    • Educational     
    • Transportation
  3. Most traditional enterprises are organized in a hierarchical manner
  4. In an enterprise, users typically fall into one of four categories:
    • Executive Management
    • Middle Management
    • Operational Management
    • Nonmanagement Employees
  5. Enterprise information is the information gathered in the ongoing operations of an enterprise-sized organization:
    • Business intelligence
    • Business process management
    • Business process automation
  6. Managers coordinate resources by performing four activities:
    • Planning
    • Organizing
    • Leading
    • Controlling
Information Systems in the Enterprise

  1. An information system is a set of hardware, software, data, people, and procedures that work together to produce information
  2. Functional units within an enterprise might include:
    • Enterprise
    • Accounting and Finance
    • Human Resources
    • Engineering or Product Development
    • Manufacturing
    • Marketing
    • Sales
    • Distribution
    • Customer Service
    • Technology
  3. Accounting software manages everyday transactions
  4. Billing software helps the company reconcile purchases with customer payments
  5. Financial software helps managers budget, forecast, and analyze
  6. A human resources information system (HRIS) manages one or more human resources functions.
  7. Employee relationship management systems manage communication between employees and the business.
  8. Computer-aided design (CAD) uses a computer and special software to aid in engineering, drafting, and design.
  9. Computer-aided engineering (CAE) uses computers to test product designs.
  10. Computer-aided manufacturing (CAM) is the use of computers to control production equipment.
  11. Computer-integrated manufacturing (CIM) uses computers to integrate the many different operations of the manufacturing process.
  12. Material Requirements Planning (MRP) uses software to help monitor and control processes related to production.
  13. Manufacturing Resource Planning II (MRP II) is an extension of MRP and also includes software that helps in scheduling.
  14. A quality control system helps an organization maintain or improve the quality of its products or services.
  15. A marketing information system serves as a central repository for the tasks of a marketing department.
  16. Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.
  17. 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
  18. Customer interaction management (CIM) software manages the day-to-day interactions with customers.
  19. 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
  20. Web site management programs collect data designed to help organizations make informed decisions regarding their Web presence
  21. 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
  22. Batch processing vs. online transaction processing.
  23. 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.
  24. Integrated Information Systems
    • Customer relationship management manages information about customers, interactions with customers, past purchases, and interests
    • Enterprise resource planning provides centralized, integrated software to help manage and coordinate ongoing activities
    • Content management systems are information systems that combine databases, software, and procedures.
Enterprise-Wide Technologies and Methodologies

  1. 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

  1. 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.
  2. Cloud computing is an Internet service that provides computing needs to computer users.
  3. Grid computing combines many servers and/or personal computers on a network to act as one large computer.
Enterprise Hardware

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

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

  1. Continuous data protection provides automatic data backup whenever data is changed in an enterprise.
  2. 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.
  3. Contains four major components.
    • Emergency plan
    • Backup plan
    • Recovery plan
    • Test plan 

Chapter 13: Computer Programs and Programming Language

What is Computer programs and programming language?

  1. A computer program is a series of instructions that directs a computer to perform tasks.
  2. Created by a programmer using a programming language.
Low‐Level Languages
  1. Machine language is the first generation of programming languages.
  2. Only language the computer directly recognizes.
  3. Assembly language is the second generation of programming languages.
  4. Programmer writes instructions using  symbolic instruction codes.
  5. A source program contains the code to be converted to machine language.
Procedural Languages

  1. In a procedural language, the programmer writes instructions that tell the computer what to accomplish and how to do it.
  2. Third-generation language (3GL)
    • A compiler translates an entire program before executing it.
    • An interpreter converts and executes one code statement at a time.
  3. The C programming language is used to write many of today’s programs.
  4. 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

  1. An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects.
  2. Other advantages include:
    • objects can be reused
    • programmers create applications faster
    • work well in a RAD environment
    • most program development tools are IDEs
  3. Java is an object-oriented programming language developed by Sun Micro systems.
  4. The Just-in-time (JIT) compiler converts the bytecode into machine-dependent code.
  5. 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.
  6. Features include:
    • CLR (Common Language Runtime) 
    • Classes
  7. C++ is an extension of the C programming language.
  8. C# is based on C++ and was developed by Microsoft.
  9. F# combines the benefits of an object-oriented language with those of a functional language.
  10. 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]
  11. A visual programming language is a language that uses a visual or graphical interface for creating all source code.
  12. Borland’s Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.
  13. Power Builder is a powerful program development RAD tool.
  14. Best suited for Web-based, .NET, and large-scale enterprise object-oriented applications.
Other Programming Languages and Development Tools

  1. 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
  2. Classic programming languages include:
    • Ada
    • ALGOL
    • APL
    • BASIC
    • Forth
    • FORTRAN
    • HperTalk
    • LISP
    • Logo
    • Modula-2
    • Pascal
    • PILOT
    • PL/1
    • Prolog
    • RPG
    • Smalltalk
  3. 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
  4. A macro is a series of statements that instructs an application how to complete a task.
  5. You usually create the macro in one of two ways:
    • Record the macro with a macro recorder
    • Write the macro
Web Page Development

  1. HTML is a special formatting language that programmers use to format documents for display on the Web.
  2. XHTML is a markup language that allows Web sites to be displayed more easily on mobile devices.
  3. XML allows Web developers to create customized tags and use predefined tags to display content appropriately on various devices.
  4. WML is a subset of XML and is used to design pages for microbrowsers.
  5. Two applications of XML are RSS 2.0 and ATOM.
  6. Web browsers can execute short programs to add interactive elements to Web pages.
  7. To send and receive information between your computer and a Web server, these programs use the CGI (common gateway interface).
  8. Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages:
    • JavaScript
    • Perl
    • PHP
    • Rexx
    • Tcl
    • VBScript
  9. Dynamic HTML  (DHTML) allows Web developers to include more graphical interest and interactivity.
  10. Cascading style sheets (CSS) contain the formats for how a particular object should be displayed.
  11. Ruby on Rails (RoR) provides technologies for developing object-oriented, database-driven Web sites.
  12. 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
  13. Most Web 2.0 sites use APIs
    • An API enables programmers to interact with an environment such as a Web site or operating system.
  14. 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

  1. Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.
    • ToolBook
    • Director
  2. Program development consists of a series of steps programmers use to build computer programs.
  3. 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
  4. 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.
    • Flow charting software makes it easy to modify and update flowcharts:
      • SmartDraw
      • Visio
    • Pseudo-code 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

  1. 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

  1. 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
  2. Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.

Step 5 – Test Solution

  1. 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

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

CHAPTER 12: Exploring Information System Development

What is Information System Development?


  1. 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).
  2. Ongoing Activities:
    • Project management
    • Feasibility assessment
    • Documentation
    • Data/information gathering
  3. System Development consist of 5 stage which is planning, analysis, design, implementation and operation,support,and security.
    • 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 
  4. System development should follow three general guidelines:
    1. Group activities or tasks into phases
    2. Involve users
    3. Define standards
  5. System development should representatives from each department in which the proposed system will be used.
  6. Project management is the process of planning, scheduling, and then controlling the activities during system development.
  7. 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
  8. 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
  9. Documentation is the collection and summary of data and information.
  10. Users and IT professionals refer to existing documentation when working with and modifying current systems.
  11. 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?

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

Planning Phase


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

Analysis Phase

  1. The analysis phase consists of two major activities:
    1. Conduct a preliminary investigation
      • Determines and defines the exact nature of the problem or improvement.
      • Interview the user who submitted the request
    2. Perform detailed analysis
      • Study how the current  system works
      • Determine the users' wants, needs, and requirement
      • Recommend a solution
  2. 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
  3. An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system.
  4. Entities are objects in the system that have data.
  5. A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.
    • Data flow
    • Processes
    • Data stores
    • Sources
  6.  The project dictionary contains all the documentation and deliverable of a project.
  7. Structured English is a style of writing that describes the steps in a process.
  8. A decision table is a table that lists a variety of conditions and the actions that correspond to each condition.
  9. A decision tree also shows conditions and actions, but it shows them graphically.
  10. The  data dictionary stores the data item's name, description, and other details about each data item.
  11. Object modeling combines the data with the processes that act on that data into a single unit, called an object.
  12. UML (Unified Modeling Language) has been adopted as a standard ntation for object modelig and development
    1. UML includes 13 different diagrams
    2. Two diagrams include:
      1. Use case diagram, A use case diagram graphically shows how actors (users) interact with the information system. Diagrams are considered easy to understand.
      2. Class diagram, A class diagram graphically shows classes and sub classes in a system. Each class can have one or more sub classes. Sub classes use inheritance methods and attributes of higher levels.
    3. The system proposal assesses the feasibility of each alternative solution.
    4. The steering committee discusses the system proposal and decides which alternative to purpyse
      • Packaged software
      • Custom software
      • Outsourcing
Design Phase

  1. The design phase consists of two major activities: 
    1. Acquire hardware and software
    2. Develop all of the details of the new or modified information system
  2. 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
  3. The next step is to develop detailed design specifications, Sometimes called a physical design
    1. Database design
    2. Input and output design
    3. Program design
  4. Systems analyst typically develop two types of designs fr each input and output.
  5. 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
  6. Computer-aided software engineering (CASE) tools are designed to support one or more activities of system development.
  7. CASE  tools sometimes contain the following tools:
    • Project repository
    • Graphically
    • Prototyping
    • Quality assurance
    • Code generator
    • Housekeeping
  8. Many people should review the detailed design specifications.
  9. An inspection is a formal review of any system development deliverable
    • A team examines the deliverables to identify errors
Implementation Phase


  1. 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
  2. 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
  3. 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
  4. 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

  1. 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
  2.  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


Monday 17 October 2016

Chapter 11 : Manage Computing Securely, Safely And Ethically

What is computer securely?

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 cyber crime is an online or Internet-based illegal act such as:

  • Hackers
  • Crackers
  • Script Kiddlies
  • Corporate Spies
  • Unethical Employees
  • Cyberextorrtionists
  • Cyber terrorists
Internet and Network Attacks
  1. Information transmitted over networks has a higher degree of security risk than information kept on an organization's premises.
  2. An online security service is a Web site that evaluates your computer to check for Internet and e-mail vulnerabilities.
  3. Computer Virus, which affects a computer negatively by altering the way the computer works. The example will be:
    • 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.
  4. 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
  5. Users can take several precautions to protect their home and work computers and mobile devices from these malicious infections.
  6. A botnet is a group of compromised computers connected to a network. A compromised computer is known as a zombie.
  7. A denial of service attack (DoS attack) disrupts computer access to Internet services.
  8. A back door is a program or set of instructions in a program that allow users to bypass security controls.
  9. Spoofing is a technique intruders use to make their network or Internet transmission appear legitimate.
  10. A firewall is hardware and/or software that protects a network's resources from intrusion.
  11. Intrusion detection software such as:
    • Analyzes all network traffic
    • Assesses system vulnerabilities
    • Identifies any unauthorized intrusions
    • Notifies network administrators of suspicious behavior patterns or system breaches.
  12. Honeypot, vulnerable computer that is set up to entice an intruder to break into it.
Unauthorized Access and Use
  1. Unauthorized access is the use of a computer or network without permission.
  2. Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.
  3. Organizations take several measures to help prevent unauthorized access and use. Team viewer is a software which let other to operate your computer from other place, but it has it own term and condition plus it required you to give the id and password to the person.
    • Acceptable use policy
    • Disable file and printer sharing
    • Firewalls
    • Intrusion detection software
  4. 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
  5. 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)
  6. 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.
  7. Digital forensics is the discovery,collection,and analysis of evidence found on computers an network.
  8. Many areas use digital forensics such as:
    • Law enforcement
    • Criminal prosecutors
    • Military intelligence
    • Insurance agencies
    • Information security department
  9. Hardware Theft and Vandalism. Hardware theft is the act of stealing computer equipment while hardware vandalism is the act of defacing or destroying computer equipment.
  10. 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

  1. Software theft occurs when someone:
    • Steals software media 
    • Intentionally erases programs
    • Illegally copies a program
    • Illegally registers and/or activates a program
  2. A single-user license agreement typically contains the following conditions:
    1. 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
    2. 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
  3. Copying,loaning,borrowing,renting,or distributing software can be a violation of copyright law.
  4. Some software requires product activation to function fully.
Information Theft
  1. Information theft occurs when someone steals personal or confidential information.
  2. Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.
  3. 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.
  4. Often used to ensure that an impostor is not participating in an Internet transaction.
  5. Web browsers and Web sites use encryption techniques.
  6. Popular security techniques include:
    • Digital certificates
    • Transport Layer Security(TLS)
    • Secure HTTP
    • VPN
System Failure
  1. A system failure is the prolonged malfunction of a computer.
  2. 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
  3. 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
  1. 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.
  2. Offsite backups are stored in a location separated from the computer site.
  3. Two categories of backups:
    1. Full backup
    2. Selective backup
  4. Three-generation backup policy:
    1. Grandparent
    2. Parent
    3. Child
Wireless Security
  1. Wireless access poses additional security risks
  2. About 80 percent of wireless networks have no security protection.
  3. War driving allows individuals to detect wireless network while driving a vehicle through the area.
  4. 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
  5. Ethics and Society
  6. Computer ethics are the moral guidelines that govern the use of computers and information systems.
  7. Information accuracy is a concern
  8. Not all information on the Web is correct
  9. Intellectual property rights are the rights to which creators are entitled for their work.
  10. An IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical. 
  11. Green computing involves reducing the electricity and environmental waste while using a computer.
  12. Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them.
  13. Huge databases store data online.
  14. It is important to safeguard your information
  15. When you fill out a form,the merchant that receives the form usually enters it into a database.
  16. Many companies today allow people to specify whether they want their personal information distributed.
  17. A cookie is a small text file that a Web server stores on your computer.
  18. 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
  19. Spam is an unsolicited e-mail message or newsgroup posting.
  20. E-mail filtering blocks e-mail messages from designated sources.
  21. Anti-spam programs attempt remove spam before it reaches your inbox.
  22. Phishing is a scam in which a perpetrator sends an official looking e-mail message that attempts to obtain your personal and financial information.
  23. Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing.
  24. Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of trust and naivety.
  25. Employee monitoring involves the use of computers to observe,record,and review an employee's use of a computer.
  26. Content filtering is the process of restricting access to certain material on the Web.
  27. Many businesses use content filtering.
  28. Internet Content Rating Association(ICRA)
  29. Web filtering software restricts access to specified Web sites.

Chapter 10 : Managing A Database

What is Database,Data,and Information?

  1. Database is collection of data organized in a manner that allows access,retrieval,and use of that data.
  2. Data is collection of unprocessed items such as:
    • Text
    • Numbers
    • Images
    • Audio
    • Video
    • Information
    • Processed data
    • Documents
    • Audio
    • Images
    • Video
  3. 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
  4. Garbage in,garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input.
  5. Valuable information should have the following characteristics:


    • Accurate
    • Verifiable
    • Timely
    • Organized
    • Accessible
    • Useful
    • Cost-effective

The Hierarchy of Data

  1. Character character is only byte, numbers,letters,space,punctuation marks,or other symbols.
  2. Field is a combination of one or more related characters
    • Field name
    • Field size
    • Data type
  3. Common data types include:
    • Text
    • Numeric
    • AutoNumber
    • Currency
    • Date
    • Memo
    • Yes/No
    • Hyperlink
    • Object
    • Attachment
    • Record
  4. A record is a group of related fields. A primary key uniquely identifies each record.
  5. A data file is a collection of related records.
What to maintaining Data?

  1. File maintenance refers to the procedure that keep data current:
    • Adding records-Users add new records to a file when they obtain new data.
    • Modifying records-Users modify a record to correct inaccurate data or update old data
    • Deleting records-When a record no longer is needed,a user deletes it from a file.
  2. 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: Let's see which one is more convenient.


  1. File processing system: 
    • Each department has its own set of files
    • Used for many years
    • Have data redundancy
    • Isolate data
  2. 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

  1. A data dictionary contains data about each file in the database and each field in those files.
  2. 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.
  3. Form is a window on the screen that provides areas foe entering or modifying data in a database.
  4. Report generator allows users to design a report on the screen,retrieve data into the report design,and then display or print the report.
  5. A DBMS provides means to ensure that only authorized users access data at permitted times.
  6. A DBMS provides a variety of techniques to restore the database to usable form in case it is damaged or destroyed. There are:
    • Backup
    • Log
    • Recovery utility
    • Continuous backup
Relational,Object-Oriented,and Multidimensional Databases

  1. A data model consists of rules and standard that define how the database organizes data.
  2. A relational database stores data in tables that consists of rows (each row has a primary key) and columns (each columns has a unique name).
  3. A relationship is a link within the data.
  4. Structured Query Language (SQL) is a query language that allows users to manage,update,and retrieve data.
  5. An object-oriented database (OODB) stores data in object.
  6. Examples of applications appropriate for an object-oriented database include:
    • Multimedia database
    • Groupware database
    • Computer-aided design database
    • Hypertext database
  7. A multidimensional database can store data in more than two dimensional of data and sometimes known as a hyper-cube. It can consolidate data much faster than a relational database
  8. A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
  9. Web Databases 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
  10. 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.
  11. 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

What is Storage?
Storage is 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 (how many GB or MB or TB).
A storage device is the computer hardware that records and/or retrieves items to and from storage media. There have 2 process which is reading and writing:

  • 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 is mean by the amount of time it takes a storage device to locate an item on a storage medium. and the time required to deliver an item from memory to the processor. If a computer access time is too long, can user stand on it?

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:

  1. Capacity
  2. platters
  3. Read/Write heads
  4. cylinders
  5. sectors and tracks
  6. revolutions per Minute
  7. Transfer Rate
  8. 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. So, how a hard disk works, please google it or youtube, it will give you a more clear picture.
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 wireless. 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.

Flash Memory Storage

  1. Flash memory chips are a type of solid state media and contain no moving parts.
  2. 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
  3. 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)
  4. USB flash drives plug into a USB port on a computer or mobile device.
Cloud Storage

Cloud Storage is an Internet service that provides storage to computer users. I phone users will be familiar with it because I phone has the function of I cloud which free for 5 GB. Users subscribe to cloud storage for a variety of reasons:

  1. Access files from any computer
  2. Store large files instantaneously
  3. Allow others to access their files
  4. View time-critical data and images immediately
  5. Store offsite backups
  6. 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. It has two type of optical discs which is read only vs. rewritable. Read only optical discs is that you cannot undo what you had burn to the optical discs while rewritable optical discs you can undo it. 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 multi session optical disc on which users can write,but not erase.
  • A CD-RW is an erasable multi session 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 100 GB.
  • DVD-RW,DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats.

Other Types of Storage

  1. 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.
  2. 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.
  3. Microfilm and microfiche store microscopic images of documents on a roll or sheet film.
  4. Enterprise storage stores huge volumes of data and information for large businesses. Uses special hardware for heavy use,maximum availability,and maximum efficiency.



Chapter 7 : Understanding Output

What is 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. For example, word that produce in monitor screen is a output of computer.

Display Devices
A display devices visually conveys text, graphics, and video information. A monitor is packaged as a separated peripheral as LCD monitor and Widescreen.

  1. Liquid crystal display (LCD) uses a liquid compound to present information on a display device.
    1. Active-matrix display
    2. Passive-matrix display
  2. The quality of an LCD monitor or LCD screen depends primarily on:
    1. Resolution, is the number of horizontal and vertical pixels in a display device.
    2. A higher resolution uses a greater number of pixels.
    3. Response time
    4. Brightness
    5. Dot pitch
    6. Contrast ratio
  3. The graphics processing unit (GPU) controls the manipulation and display of graphics on a display device. 
  4. LCD monitors use a digital signal and should plug into a DVI port, an HDMI port, or a Display port. 
  5. 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. 
    1. Require a convert if you are connecting your computer  to an analog television. 
    2. Digital television (DTV) offers a crisper, higher-quality output. HDTV is the most advanced form of digital television.
  6.  A CRT monitor is a desktop monitor that contains a cathode-ray tube. Have a much larger footprint than do LCD monitors.


Is that amazing? Electronic device that surround us can consider as output. Smart phone also one of output device.

Printers is also a output device. A printer produces text and graphics on a physical medium. Printed information is called a hard copy, or printout. Hard copy can be landscape or portrait orientation. People use printer to print document and photo. Nowadays, printer can be connect to internet by using WIFI, so, we just need to connect to the printer, without opening computer, we can print our stuff.
Printer have few type:A non-impact printer  forms characters and graphics on a piece of paper without actually striking the paper.
  1. Ink-jet printers, forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper. It can be color or black and white printout. Printers with a higher dpi (dots per inch) produce a higher quality output.
  2. Photo printers, produces color photo-lab-quality pictures. Most use ink -jet technology PictBridge allows you to print photos directly from a digital camera. It can print from a memory card and preview photos on a built-in LCD screen.
  3. Laser printers which is High speed and High Quality. It has Black and white, and Color
  4. Thermal printers generates images by pushing electrically heated pins against the heat sensitive paper. 
  5. 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.
  6. Label and postage printers
    • A label printer is a small printer that prints on adhesive-type material.
    • A postage printer prints postage stamps. Postage also can printed on other types of printers.
  7. Plotters are used to produce high quality drawings.
  8. Large format printers create photo-realistic quality color prints on a larger scale. For example banner.
  9. A multi function peripheral (MFP) is a single device that prints, scans, copies, and in some cases, faxes. Sometimes called an all in one device.
  10. 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 which produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon.
    • Line printer which prints an entire line at a time.
When we want to listen to music, what we will use? IS Speakers, Headphones, and Earbuds which is 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 many people use to connect to smart phone and computer. Bluetooth speaker also popular.

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.

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