Computers enable the efficient processing and storage of information. They are composed of hardware and software and exist in a variety of sizes, from embedded computers inside devices to supercomputers used for highly complex tasks. A basic computer system includes input devices like a keyboard, a central processing unit that performs calculations, and output devices like a monitor that present results.

1. Introduction to Computers

2. Introduction to Computers We are living in an information age dependent upon digital information. Digital information is electronic information, the result of computer processing . Every type of job relies upon getting information, using it, managing it, and relaying information to others. Computers enable the efficient processing and storage of information.

3. Computers around us… Do not think of a computer merely as the machine with the keyboard and the mouse, although that might be true for some types of computers. Embedded computers may be inside your household appliances, the VCR, the automobile, planes, trains, powerplants, water purification plants, calculators, and even inside a few toys. These embedded computers are very small. They affect our lives each day. Why, even modern traffic lights operate with computers. They are all around us. Think of additional ways in which computers affect our lives each day.

4. What is a Computer? An electronic device that stores, retrieves, and processes data, and can be programmed with instructions. A computer is composed of hardware and software, and can exist in a variety of sizes and configurations.

5. Uses of Computer PC at Home Common uses for the computer within the home Computer games Working from Home Banking from Home Connecting to the Web

6. Uses of Computer Office Applications Stock Control Stock control is ideal for automation and in many companies it is now completely computerized. The stock control system keeps track of the number of items in stock and can automatically order replacement items when required. Accounts / Payroll In most large organizations the accounts are maintained by a computerized system. Due to the repetitive nature of accounts a computer system is ideally suited to this task and accuracy is guaranteed.

7. Uses of Computer Automated Production Systems Many car factories are almost completely automated and the cars are assembled by computer-controlled robots. This automation is becoming increasingly common throughout industry. Design Systems Many products are designed using CAD (Computer Aided Design) programs to produce exact specifications and detailed drawings on the computer before producing models of new products.

8. Uses of Computer Computers in Daily Life Accounts Games Educational On-line banking Smart ID cards Supermarkets Working from home (Tele-working) Internet

9. Types of Computers Supercomputers A computer that led the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. The term "Super Computing" was first used by New York World newspaper in 1920 to refer to large custom -built tabulators IBM made for Columbia University.

10. Used for highly calculation-intensive tasks Supercomputers are used for highly calculation-intensive tasks such as problems involving quantum mechanical physics, weather forecasting, climate research (including research into global warming), molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals), physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion), cryptanalysis, and the like. Major universities, military agencies and scientific research laboratories are heavy users.

11. Mainframe Computer Mainframes (often colloquially referred to as Big Iron ) are computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics and financial transaction processing. Nearly all mainframes have the ability to run (or "host") multiple operating systems and thereby operate not as a single computer but as a number of virtual machines. In this role, a single mainframe can replace dozens or even hundreds of smaller servers, reducing management and administrative costs while providing greatly improved scalability and reliability.

12. Mainframe Computer A very large computer capable of supporting hundreds, or even thousands, of users simultaneously. Mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe.

13. Minicomputer Minicomputer (colloquially, mini ) is a term for a class of multi-user computers which make up the middle range of the computing spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or personal computers) Minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously.

14. Microcomputer The term microcomputer is generally synonymous with personal computer (PC), or a computer that depends on a microprocessor. A microcomputer (sometimes shortened to micro ) is a computer with a microprocessor as its CPU. Another general characteristic of these computers is that they occupy physically small amounts of space.

15. Microcomputer The microcomputer came after the minicomputer, most notably replacing the many distinct components that made up the minicomputer's CPU with a single integrated microprocessor chip. Cheap and easy to use. Often used as stand-alone computers or in a network. May be connected to large mainframe computers within big companies.

16. Microcomputer Model Floor Model Briefcase

17. Microcomputer Model Desktop Notebook Laptop Subnotebook Palmtop

18. COMPUTER SYSTEM KEYBOARD PROCESSOR MONITOR PRINTER Storage devices

19. Computer System A computer system consists of three primary units: Input units – accept data Processor unit – processes data by performing comparisons and calculations Output units – present the results

20. Input Devices Data are facts, numbers and characters that are entered into the computer via keyboard. Other types of input devices are mouse, joystick, light pens, scanners, camera, etc.

21. Processor Unit Two main parts: CPU – where the actual processing takes place; and Main memory – where data are stored. The contents of main memory can be transferred to auxiliary storage devices such as hard disks, floppy diskettes, zip disks, compact disks, or USB flash disk.

22. Output Unit After the data has been processed, the results are output in the form of useful information. Output units such as monitors and printers make the result accessible for use by people.

23. Hardware ,Software & Peopleware The term hardware refers to the physical components of your computer such as the system unit, mouse, keyboard, monitor etc. The software is the instructions that makes the computer work. Software is held either on your computers hard disk, CD-ROM, DVD or on a diskette (floppy disk) and is loaded (i.e. copied) from the disk into the computers RAM (Random Access Memory), as and when required. Peopleware means the programmers, students, teachers and other users and/or operators of the computers.

24. Four Operations of a Computer System Input - Home computers are microcomputers. Input is supplied to the microcomputer with the use of a keyboard, a mouse, or another input device. These input devices may be called peripheral devices . Processing - Processing is done inside the computer in an area called the central processing unit (CPU) . Processing is the conversion of input to output. Storage refers to holding information somewhere. RAM, Random Access Memory, is short-term memory. It is volatile memory because the memory is automatically "erased" when the power is turned off or interrupted. The RAM memory is located inside the computer case on the motherboard. A motherboard is not the keyboard.

25. Four Operations of a Computer System The keyboard is what you type with. A motherboard holds RAM memory, electronic circuits and other computer parts including the central processing unit. ROM, Read-Only-Memory, is not volatile meaning the memory is still there when power is interrupted or turned off. When the computer is turned back on again, ROM memory is still in storage on the internal hard disk. 4. Output is the result of a computer process. Output may be viewed on a monitor screen, heard through speakers, printed on printers, and so forth. Output devices may be considered hardware and are also considered to be peripheral devices .

26. A Basic Computer "System" A computer system refers to the computer AND all of its equipment. Equipment like speakers, printer, keyboard, scanner, etc. is called peripheral equipment, sometimes shortened to "peripherals". The central processing unit (CPU) is considered to be "the computer" . Without peripheral equipment (such as monitor, printer, speakers, etc.) for input and output the microcomputer (home computer) will not be able to do anything you find useful. Your computer system cannot help you type a letter unless you have some type of software (program) to do this. Most typing is handled by a "word processing" program. A software program for your computer can be purchased at stores such as Windows 7 or for free like UBUNTU or Linux.