Chapter #14 Enterprise Computing

What is 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 :

1. Retail
2. Manufacturing
3. Service
4. Wholesale
5. Government
6. Educational
7. Transportation

• Most traditional enterprises are organized in a hierarchical manner.
• In an enterprise, users typically fall into one of four categories :

1. Executive Management
2. Middle Management
3. Operational Management
4. Nonmanagement Employees

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

1. Business intelligence
2. Business process management
3. Business process automation

• Managers coordinate resources by performing four activities :

1. Planning
2. Organizing
3. Leading
4. 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 :

1. Accounting and Finance
2. Human Resources
3. Engineering or Product Development
4. Manufacturing
5. Marketing
6. Sales
7. Distribution
8. Customer Service
9. Information Technology

• Accounting software manages everyday transactions.
• Billing software helps the company reconcile purchases with customer payments.
• Financial software helps manager budget, forecast, and analyze.
• A human resources information system (HRIS) manages one or more human resources functions.
• Employee relationship management systems mange 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 :

1. Provide forecasting for inventory control
2. Manage and track shipping of products
3. 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.

1. Whether to build or buy new information systems.
2. 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.

1. Office Information System
2. Transaction Processing System
3. Management Information System
4. Decision Support System
5. Expert System

• Batch processing vs. online transaction processing.
• Integrated Information Systems

1. Customer relationship management manages information about customers, interactions with customers, past purchases, and interests.
2. Enterprise resource planning provides centralized, integrated software to help manage and coordinate ongoing activities.
3. Content management systems are information systems that combine databases, software, and procedures.

Enterprise-Wide Technologies and Methodologies

• Some technologies used in enterprise include :

1. Protals
2. Data warehouses
3. Electronic data interchange
4. Extranets
5. Web services
6. Document management systems
7. Workflow
8. Virtual private networks

• A portal is a collection of links, content and services presented on a Web page that are interesting for a particular job function.
• A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
• EDI is a set of standards that controls the transfer of business data and information among computers both within and among enterprises.
• 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 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.
• A document management system (DMS) allows for storage and management of a company's documents. - Stored in a repository
• A workflow is a defined process that identifies the specific set of steps involves in completing a particular project or business process. - Workflow application 
• 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.

Enterprise Hardware

• Enterprise hardware allows large organizations to manage and store information and data using devices geared for :

1. Heavy use
2. Maximum availability
3. 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, 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 how-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 : 

1. Emergency plan
2. Backup plan
3. Recovery plan
4. Test plan 

Chapter #13 Computer Programs and Programming Languages

Computers 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)

1. A compiler translates an entire program before executing it.
2. 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 :

1. Objects can be reused
2. Programmers create applications faster
3. Work well in a RAD environment
4. 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 cmputers and mobile devices.
• Features include :

1. CLR (Common Language Runtime)
2. 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

1. Visual Basic is based on the BASIC programming language.
2. Visual C++ is based on C++.
3. 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.

Other Programming Languages and Development Tools

• Best suited for WEB-based, .NET, and large-scale enterprise object-oriented applications.
• A 4GL (forth-generation language) is a nonprocedural language that enables users and programmers to access data in database - One popular 4GL is SQL.
• Classic programming languages include :

1. Ada
2. ALGOL
3. APL
4. BASIC
5. Forth
6. FORTRAN
7. HyperTALK
8. LISP
9. Logo
10. Modula-2
11. Pascal
12. PILOT
13. PL/1
14. Prolog
15. RPG
16. Smalltalk

• An application generator is a program that creates source code or machine code form 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 :

1. Record the macro with macro recorder
2. 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 micro browsers. 
• 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)

1. Scripts
2. Applets
3. Servlets
4. ActiveX controls

• Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages.

1. JavaScript
2. Perl
3. PHP
4. Rexx
5. Tcl
6. VBScript

• Web 2.0 allows Web sites to provide a means for users to :

1. Share personal information
2. Allow users to modify Web site content
3. Have application software built into the site

• Most Web 2.0 sistes 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.

1. Dreamweaver
2. Expression Web
3. Flash
4. SharePoint Designer

Multimedia Program Development

• Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.

1. ToolBook
2. Director

Program Development

• Program development consists of a series of steps programmers use to build computer programs.

Step 1 - Analyze Requirements

• To initiate program development, programmer :

1. Reviews the requirements
2. Meets with the systems analyst and users
3. Identifies input, processing, and output

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.
• The sequence control structure shows one or more actions following each other on order.
• The selection control structure tells the program which action to take, based on a certain condition.

1. If-then-else
2. 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.

1. SmartDraw
2. 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

1. Develop various sets of test data
2. Determine the expected result
3. Step through the algorithm
4. Compare the results
5. 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 :

1. Generating or providing some or all code.
2. Writing the code that translates the design into a computer program.
3. 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.

1. Errors include syntax errors and logic errors.
2. Debugging the program involves removing the bugs.
3. 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 :

1. Review the program code
2. Review all the documentation

Chapter #12 Exploring Information System Development

What is System Development ?

• System development is a set of activities used to build an information system.

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

• System development should follow three general guidelines :

1. Group activities or tasks into phases
2. Involve users
3. Define standards 

• System development should involve 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 :

1. Project scope
2. Required activities
3. Time estimates for each activity
4. Cost estimates for each activity
5. Order of activities
6. Activities that can take place at the same time

• A popular tool used to plan and schedule the time relationships among project activities is a Gantt chart.
• A PERT chart also can be used for planning and scheduling time.
• Feasibility is a measure of how suitable the development of a system will be to the organization.

1. Operational feasibility 
2. Schedule feasibility
3. Technical feasibility
4. 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.

1. Review documentation
2. Observe
3. Survey
4. Interview
5. JAD Sessions
6. 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 :

1. Review and approve the project requests
2. Prioritize the project requests
3. Allocate resources
4. Form a project development team

Analysis Phase

• The analysis phase consists of two major activities :
• Conduct a preliminary investigation 

1. Determines and defines the exact nature of the problem or improvement.
2. Interview the user who submitted the request.

• Performed detailed analysis

1. Study how the current system works.
2. Determine the users' requirements.
3. Recommend a solution.

• Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs.

1. Entity-relationship diagrams
2. Data flow diagrams
3. 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.

1. Data flows
2. Processes
3. Data stores
4. 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 other.
• 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 notation for object modeling and development .

1. UML includes 13 different diagrams
2. Two diagrams include : Use case diagram & Class diagram

• A use case diagram graphically shows how actors (users) interact with the information system.
• Diagrams are considered easy to understand.
• A class diagram graphically shows classes and subclasses in a system.
• Each class can have one or more subclasses.
• Subclasses use inheritance to inherit methods and attributes of higher levels.
• The system proposal assesses the feasibility of each aternative solution.
• The steering committee discusses the system proposal and decides which alternative to pursue.

1. Package software
2. Custom software
3. Outsourcing

Design Phase

• 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.

• To acquire the necessary hardware and software :

1. Identify technical specifications
2. Solicit vendor proposals
3. Test and evaluate vendor proposals
4. Make a decision 

• 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

• Systems analysts typically develop two types of designs for each input and output.
• A prototype (proof of concept) is a working model of the proposed system.

1. Prototypes have inadequate or missing documentation.
2. Users tend to embrace the prototype as a final system.
3. Should not eliminate or replace activities.

• Computer-aided software engineering (CASE) are designed to support one or more activities of system development.
• CASE tools sometimes contain the following tools :

1. Project repository
2. Graphics
3. Prototyping
4. Quality assurance
5. Code generator
6. 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 them deliver it.

1. Develop programs
2. Install and test the new system
3. Train users
4. Convert to the new system

• The program development life cycle follows these steps :

1. Analyze the requirements
2. Design the solution
3. Validate the design
4. Implement the design
5. Test the solution
6. Document the solution

• Various tests should be performed on the new system.
• Unit test - Verifies that each program or object works by itself.
• Systems test - Verifies that all programs in an application work together properly.
• Integration test - Verifies that an application works with other applications.
• Acceptance test - Checks the new system to ensure that it works with actual data.
• Training involves showing uses exactly how they will use the new hardware and software in the system.

1. One-on-one sessions
2. Classroom-style lectures
3. Web-based training

• One or more of 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.

1. Perform maintenance activities
2. Monitor system performance
3. Assess system security

• A computer security plan should do the following :

1. Identify all information assets of an organization.
2. Identify all security risks that may cause an information asset loss.
3. For each risk, identify the safeguards that exist to detect, prevent, and recover from a loss.

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

1. Hackers
2. Crackers 
3. Script Kiddies
4. Corporate Spies
5. Unethical Employees
6. Cyberextortionists
7. 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 :

1. Operating system runs much slower than usual
2. Available memory is less than expected
3. Files become corrupted
4. Screen displays unusual message or image
5. Music or unusual sound plays randomly
6. Existing programs and files disappear
7. Programs or files do not work properly
8. Unknown programs or files mysteriously appear
9. System properties change 
10. Operating system does not start up
11. 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 instruction 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

1. Analyzes all network traffic
2. Assesses system vulnerabilities
3. Identifies any unauthorized intrusions
4. Notifies network administrators of suspicious behavior patterns or system breaches

• Honeypot

1. 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 of its data for unapproved or possibly illegal activities.
• Organizations take several measures to help prevent unauthorized access and use

1. Acceptable use policy
2. Disable file and printer sharing
3. Firewalls
4. Intrusion detection software

• Access controls define who can access a computer, when they can access it, and what actions they can take

1. Two-phase processes called identification and authentication
2. User name
3. Password
4. Passphrase
5. 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 device authenticates a person's identity by translating a personal characteristics 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 and networks.
• Many areas use digital forensics

1. Law enforcement
2. Criminal prosecutors
3. Military intelligence
4. Insurance agencies
5. Information security departments

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.

1. Physical access controls
2. Alarm systems
3. Cables to lock equipment
4. Real time location system
5. Passwords, possessed objects, and biometrics

Software Theft 

• Software theft occurs when someone :

1. Steals software media
2. Intentionally erases programs
3. Illegally copies a program
4. Illegally registers and/or activates a program

• A single-user license agreement typically contains the following conditions :

Permitted to :

1. Install the software on one computer
2. Make one copy of the software
3. Remove the software from your computer before giving it away or selling it

Not permitted to :

1. Install the software on a network
2. Gibe copies to friends or colleagues while continuing to use the software
3. Export the software
4. 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 occurs when someone steals personal or confidential information.
• Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.
• A digital signatures 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 :

1. Digital Certificates
2. Transport Layer Security (TLS)
3. Secure HTTP
4. VPN

System Failure

• A system failure is the prolonged malfunction of a computer.
• A variety of factors can lead to system failure, including :

1. Aging hardware
2. Natural disasters
3. Electrical power problems (Noise, undervoltages, and overvoltages)
4. 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.
• Offsite backups are stores in a location separate from the computer site.
• Two categories of backups :

1. Full backup
2. Selective backup

• Three-generation backup policy 

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 networks while driving a vehicle through the area.
• In additional to using firewalls, some safeguards improve security of wireless networks :

1. A wireless access point should not broadcast an SSID
2. Change the default SSID
3. Configure a WAP so that only certain devices can access it
4. 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. - A copyright protects any tangible form of expression.
• 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 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 :

1. Allow for personalization
2. Store users' passwords
3. Assist with online shopping
4. Track how often users visit a site
5. Target advertisement

• Spam is an unsolicited e-mail message or newsgroup posting.
• W-mail filtering block e-mail messages from designated sources.
• Anti-spam programs attempt to 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 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 or restricts access to specified Web sites.

Chapter #10 Managing a Database

Databases, Data, and Information

• Database

1. Collection of data organized in a manner that allows access, retrieval, and use of the data.

• Data

1. Collection of unprocessed items
2. Text
3. Numbers
4. Images
5. Audio
6. Video

• Information

1. Processed data 
2. Documents 
3. Audio
4. Images 
5. Video

• Database software, often called a database management system (DBMS), allows users to :

1. Create a computerized database
2. Add, modify, and delete data
3. Sort and retrieve data
4. 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 characterictics :

1. Accurate
2. Verifiable
3. Timely
4. Organized
5. Accessible
6. Useful
7. Cost-effective

The Hierarchy of Data

• A character is one byte - Numbers, letters, space, punctuation marks, or other symbols.
• A field is a combination of one or more related characters

1. Field name
2. Field size
3. Data type

• Common data types include:

1. Text
2. Numeric
3. AutoNumber
4. Currency
5. Date
6. Memo
7. Yes/No
8. Hyperlink
9. Object
10. Attachment

• A record is a group of related fields - A primary key uniquely identifies each record.
• A data file is a collection of related records.

Maintaining Data

• File maintenance refers to the procedures that keep data current

1. Adding records
2. Modifying records
3. 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

1. Alphabetic/Numeric check
2. Range check
3. Consistency check
4. Completeness check
5. Check digit
6. Other checks

File Processing Versus Databases

• File processing system

1. Each department has its own set of files
2. Used for many years
3. Have data redundancy
4. Isolate data

• Databases approach

1. Programs and users share data
2. Reduce data redundancy
3. Improve data integity
4. Share data
5. Allows easier access
6. Reduces development time
7. 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

1. Query language
2. Query by example
3. Form
4. Report generator

• A query language consists of simple, English-like statements that allows users to specify the data to display, print, or store.
• Query by example (QBE) provides a GUI to assist users with retrieving data.
• A form is a window on the screen that provides area for entering or modifying data in a database.
• A report generator allows users to design a report on the screen, retrieve data into the report design, and then display or print the report.
• A DBMS provides means to ensure that only authorized users access data at permitted times.

1. Access privileges
2. Principle of least privilege

• A DMBS provides a variety of techniques to restore the database to a usable form in case it is damaged or destroyed

1. Backup
2. Log
3. Recovery utility
4. Continuous backup

Relational, Object-Oriented, and Multidimensional Databases

• A data model consists of rules and standards that define how the database organizes data.
• A relational database stores data in tables that consist of rows and columns.

1. Each row has a primary key
2. Each column 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 objects.
• Examples of applications appropriate for an object-oriented database include :

1. Multimedia database
2. Groupware database
3. Computer-aided design database
4. Hypertext database

• A multidimensional database can store data in more than two dimensions of data

1. Sometimes known as a hypercube
2. 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 :

1. Shop for products or services
2. Buy or sell stocks
3. Search for a job
4. Make airline reservations
5. Register for college classes
6. Check semester grades

Database Administration

• It is important to have a carefully designed database.
• Employees should learn how to use the data in the database effectively.

1. Interact with database
2. Identify new data for the database
3. Maintain the database

Chapter #9 Networks and Communications

COMMUNICATIONS

• Computer communications describes a process in which two or more computers or devices transfer data, instructions, and information.

USES OF COMPUTER COMMUNICATIONS

• Blogs
• Chat rooms
• E-mail
• Fax
• FTP
• Instant messaging 
• Internet
• Newsgroup
• RSS
• Video conferencing
• VoIP
• Web
• Web 2.0
• Web folder
• Wikis

• Users can send and receive wireless messages using wireless messaging services.
• Wireless Internet access points allow people to connect wirelessly to the Internet from home, work, school, and in many public locations.
• A cybercafe is a coffeehouse, restaurant, or other location that provides personal computers with Internet access to its customers.
• A global positioning system (GPS) is a navigation system that consists of one or more earth-based receivers that accept and analyze signals sent by satellites in order to determine the GPS receiver,s geographic location.
• Groupware

1. Helps groups of people work together on projects and share information over a network.
2. Component of workgroup computing.
3. Major feature is group scheduling.

• Voicemail

1. Allows someone to leave a voice message for one or more people.
2. Computer in voicemail system converts an analog voice message into digital form.
3. A voice mailbox is a storage location on a hard disk in the voice mail system.

• Many programs provide a means to collaborate, or work online, with other users connected to a server.
• Collaboration software includes tools that enable users to share documents via online meetings and communicate with other connected users.
• Web services enable programmers to create applications that communicate with other remote computers over the internet or on an internal business network.
• A mashup is a web application that combines services from two or more sources.
• A network is a collection of computers and devices connected together via communications devices and transmission media.

NETWORKS

• Advantages of a network include:

1. Facilitating communications
2. Sharing hardware 
3. Sharing data and information
4. Sharing software 
5. Transferring funds

• A local area network (LAN) is a network that connects computers and devices in a mimited geographical area.
• A wireless LAN (WLAN) is a LAN that uses no physical wires.
• A metropolitan area network (MAN) connects LANs in a metropolitan area.
• A wide area network (WAN) is a network that covers a large geographical area.
• The design of computers, devices, and media on a network is sometimes called the network architecture.
• P2P describes an Internet network on which users access each other's hard disks and exchange files directly over the Internet.
• A network topology refers to the layout of the computers and devices in a communications network.
• An internet is an internal network that uses Internet technologies.
• An extranet allows customers or suppliers to access part of its intranet.

Network Communications Standards 

1. Ethernet
2. Token ring
3. TCP/IP
4. Wi-Fi
5. Bluetooth 
6. UWB 
7. IrDA
8. RFID
9. WiMAX
10. WAP

• Ethernet is a network standard that specifies no computer controls when data can be transmitted.
• The token ring standard specifies that computers and devices on the network share or pass a special signal (token).
• TCP/IP is a network standard that defines how messages are routed from one end of a network to another.
• Wi-Fi identifies any network based on the 802.11 standard that facilities wireless communication.
• Sometimes referred to as wireless Ethernet.
• Bluetooth defines how two Bluetooth devices use short-range radio waves to transmit data.
• UWB (ultra-wideband) specifies how two UWB devices use short-range radio waves to communicate at high speeds.
• IrDA transmits data wirelessly via infrared (IR) light waves.
• RFID uses radio signals to communicate with a tag places in or attached to an object, animal, or person.
• WiMAX (802.16)

1. Developed by IEEE
2. Towers can cover a 30-mile radius
3. Two types are fixes wireless and mobile wireless
4. Provides wireless broadband Internet access

• Wireless Application Protocol (WAP)

1. Specifies how some mobile devices can display the content of Internet services
2. Web 
3. E-mail
4. Chat rooms
5. Uses a client/server network

Communications Software

• Communication software consists of programs that :

1. Help users establish a connection to another computer or network.
2. Manage the transmission of data, instructions, and information.
3. Provide an interface for users to communicate with one another.

Communications Over the Telephone Network

• The public switched telephone network (PSTN) is the worldwide telephone system.

1. Dial-up ines
2. Dedicated line
3. ISDN line
4. DSL
5. FTTP
6. T-carrier line
7. ATM

• ADSL connections transmit data downstream at a much faster rate than upstream.

Communications Devices

• A communications device is any type of hardware capable of transmitting data, instructions, and information between a sending device and a receiving device.
• A dial-up modem converts signals between analog and digital.
• A digital modem sends and receives data and information to and from a digital line.

1. DSL modem
2. Cable modem

• A wireless modem uses the cell phone network to connect to the Internet wirelessly form a notebook computer, a smart phone, or other mobile device.
• A network card enables a computer or device to access a network.
• Available in a variety of styles.
• Wireless network cards often have an antenna.
• A wireless access point is a central communications device that allows computers and devices to transfer data wielessly among themselves or to a wired network.
• A router connects multiple computers or other routers together and transmits data to its correct destination on a network.
• Many are protected y a hardware firewall.
• A hub or switch connects several devices in a network together.

Home Networks

• Home networks provide computers with the following capabilities :

1. Connect to the Internet at the same time
2. Share a single high-speed Internet connection
3. Access files and programs on other computers
4. Share peripherals
5. Play multiplayer games
6. Connect game consoles to the Internet
7. Subscribe to and use VoIP

• Types of wired home networks :

1. Ethernet
2. Powerline cable
3. Phoneline

Communications Channel

• The amount of data that can travel over a communications channel sometimes is called the bandwidth.
• Latency is the time it takes a signal to travel from one location to another on a network.
• Transmission media carries one or more signals.
• Broadband media transmit multiple signals simultaneously.

Wireless Transmission Media

• Cellular radio is a form of broadcast radio that is used widely for mobile communications.
• Microwaves are radio waves that provide a high-speed signal transmission.
• A communications satellites is a space station that receives microwaves signals from an earth-based station, amplifies it, and broadcasts the signal over a wide area.

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, instructions, 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.

1. Reading is the process or transferring items from a storage medium into memory.
2. Writing is the process of transferring items from memory to a storage medium.

• Access time measures : 

1. The amount of time it takes a storage device to locate an item on a storage medium.
2. The time required to deliver an item from memory to the processor.

Hard Disk

• 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 Minutes
7. Transfer Rate
8. Access Time

• Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.
• 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.
• RAID (redundant array of independent disks) is a group of two or more integrated hard disks.
• A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage.
• An external hard dish 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.

1. SATA
2. EIDE
3. SCSI
4. 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 :

1. Faster access time
2. Faster transfer rates
3. Generate less heat and consume less power
4. 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.

1. Compact Flash (CF)
2. Secure Digital (SD)
3. Secure Digital High Capacity (SDHC)
4. microSD
5. microSDHC
6. xD Pictue Crd
7. Memory Stick
8. 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 computer.

Cloud Storage

• Cloud storage in an Internet service that provides storage to computer users.
• 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.
• Read only vs. re-writable.
• 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.
• Care of optical discs.
• 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 and erasable multi-session disc - Must have a CD-RW drive.
• Archive disc :

1. Stores photos from an online photo center
2. Resolution usually is 7200 pixels per photo
3. Cost is determines by the number of photos being stored

• Picture CD :

1. Single-session CD-ROM that stores digital versions of film
2. Typically uses a 1024 x 1536 resolution
3. Many photo centers offer Picture CD services

• 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-caacity rewritable DVD formats

Other Types of Storage

• Tape 
• Magnetic stripe cards and smart cards
• Microfilm and microfiche
• Enterprise storage
• 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.
• 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 image of documents on a roll or sheet film.
• 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

1. 500 GB hard disk
2. Cloud storage
3. Optical reader/writer
4. USB flash drive

• Small office/Home Office user

1. 1 TB hard disk
2. Cloud storage
3. Optical disc drive
4. External hard disk for backup
5. USB flash drive

• Mobile

1. 250 GB hard disk
2. Cloud storage
3. Optical disc drive
4. Card reader/writer
5. Portable hard disk for backup
6. USB flash drive

• Power User

1. 2.5 TB hard disk
2. Cloud storage
3. Optical hard drive
4. Portable hard disk for backup
5. USB flash drive

• Enterprise User (desktop computer)

1. 1 TB hard disk
2. Optical disc drive
3. Smart card reader
4. Tape drive
5. USB flash drive

• Enterprise User (server or mainframe)

1. Network storage server
2. 40 TB hard disk system
3. Optical disc server
4. Microfilm or microfiche