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Description

Introduction Computers are information processing machines used in different departments and organizations. They can be connected all over the world. Therefore, more productivity and good quality with less cost and legal constrains Computers perform three main operations: 1. Receive input (data raw facts) 2. Process it according to predefined instructions 3. Produce out output (information which is meaningful data). Computer system The components of computer system are: 1. Hardware: Physical components like Screen, Cables, keyboard, system box and printer. The hardware cannot do any thing without software. 2. Software: A set of instructions that tell computer what to do and how to do it. Such as: word processing, computer Games and Graphics Programs. Software is a collection of programs, data, and information. A program is a set of sequence instructions that tell the computer what to do. Hardware built on physical equipment but software (logical component) is built on thinking, knowledge and planning. A programmer is the person who makes the program using one of the computer's programming languages. 3. Users: A person who use the software on the computer to do some task. Computer Software There are two kinds of software: system software and application software 1. system software: it is the software used by the computer or operator's computer system such as operating systems

operating systems: the most important system software. It is holds all instructions that make computer; displaying on the monitor; using the keyboard; saving and loading files; using secondary memory, managing Application software by being an interface between them and computer's equipment. Usually an O.S is supplied with the computer on hard disk, and it is loading into computer memory automatically when the computer is switched on. Some times you have to in put some information to configure your computer like adding printer functions of operating systems 1. booting up 2. user interface 3. task and resources management 4. monitoring 5. files management 6. system security 2. application software: It is the software used by users like word processors, Spreadsheets, databases, graphics and drawing programs, presentation tools interface : It is the way that user used to deal with the computer or communication his commands to the computer  command line interface: Commands had to be typed on a keyboard as a line of text. It is slow process, and required a high degree of computer knowledge.  Graphic user interface (GUI): Uses pictures; windows; menus; and Icons to represent to objects and commands. The users can select his needs by pointing the mouse at and then clicking on it.

System development Involves the design, development, and implementation of computer operations to replaced or update some processes within the organization. Steps of system development 1. Define requirements: understand the business problem or opportunity 2.Assess feasibility: to determine whether a new or improved information system is a feasible solution 3.System analysis: Analyze the information needs of end-users, the organizational environment and any system presently used 4.Product development for the hardware, software, people and data resources, and the information products that will satisfy the functional requirements of the proposed system. 5.Testing: test the system 6.Training: train people to operate and use it 7.Hand over to the client. 8.Monitoring and maintaining the system: use a post- implementation review process to monitor, evaluate, and modify the system as needed

Information technology (IT) A set tools that are used to: receive, process, store retrieve, print and transmit information in an electronic form through computers these form can be: text, sound, picture or video. Different between computer and people Computer are good for repetitive tasks, and for those tasks that require high speed. Accuracy and calculations. They are good for combining, storing, and retrieving data. People are good in tasks that require creativity and imagination where instructions cannot be written. They are better for non-repetitive tasks, as well as, for tasks that need feelings. The computer versus people debate has developed into the context of information and communications technology being an integral part everyday life. The European commission posted some questions. The considered opinion was that computer literacy skill have become as important as traditional skills of reading, writing and arithmetic. It enables people to take advantage of the opportunities at work, as well as to practice fully in all other aspect of life. Computer use Computer play an important role in societies. They are used in different fields as we mentioned. Computer use leads to:  The eliminate repetitive tasks  Providing greater efficiency and reliability in processing of information  Providing a new employment opportunity  Getting a large amount of information from the internet in your home.

 Doing your task quickly and easily from the home like making reservations, buying and purchasing via internet and sending messages via e-mail  Working from home by use telecommunications  Firms, which can sell directly to people in their homes. There is not any need for renting stores.  Teleconferencing and video conferencing.  The rapid development in machines and equipment.  The standards of living, which are changed to higher level. Computers at work Many different types of computer system are used according the type of business. Usually the computers are with high specifications for processing data. They are linked to make a net work. Other peripherals used are: the scanner, touch screens, bar code readers and the modem and internet server. The software, which is used, is word process, spreadsheet, databases, graphics programs, presentation programs, e-mail and communications programs, accounting and finance packages, statistics packages, a calendar program, decision support systems and project management, and other tools Computer in education Computers are used in universities, collage, training, research and administration. Usually the hardware is a network or standalone computers with special tools. For administrations the software is word process, database and programs, training programs, word process, spreadsheet, desktop publishing programs finance packages. For class room use, there are educational packages, multimedia authoring, internet and e-mail and presentation and graphics packages.

security

involves not only the physical security of computer equipment, but also the security of the data contained on the storage media 1. the computer should be protected from damage (hardware and software) 2. data should be backed up and protected from viruses 3. passwords must be used for hardware and software 4. back-ups are essential. Backups They are copies of all software files and information when you have in your computer system; use it when the original copies are damage because of physical failure use errors; accidents, or carelessness Backups can be made by different methods: 1. copying onto CD or external hard disk 2. copying onto remote servers 3. copying a hardcopy in all cases: 1. backup must be made on regular basis. 2. the user can use back-up programs that make the operation automatic in special times 3. keeping back-ups in a secure and safe place 4. make different copies and keep them different locations 5. label each CD or external hard disk. 6. disks should be write protected....