Computer is defined as a combination of electro-mechanical devices (Hardware) capable of accepting data or information, processing, storing, and providing output under the control of some instructions and commands called programs (Software).
Computers are machines that perform tasks or calculation according to a set of instruction or programs. Introduce in 1940s the first fully electronic computers were huge machines that required teams of people to operate. Compared to those early computers, today’s computers are amazing, not only are they thousand of times faster, they can fit on your desk, in your lap, or even in your pocket. Computers work through an interaction of hardware and software. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. The most important piece of hardware is a tiny rectangular chip inside your computer called the central processing unit (CPU) or microprocessor. It is the (brain) of the computer that translates instructions and performs calculations.
Computer performs three functions while processing data:-
i. Input: the computer accepts data from outside for processing within. ii. Storage: computer holds data internally for processing within. iii. Processing: the computer performs operation on the data it holds within.
2. IMPORTANT COMPONENTS
The basic components of a desktop computer are the Power Cord, System Unit, Monitor, Keyboard, mouse, Diskette, Flash drives, Printer and Speakers. Each part plays an important role whenever a computer is being used.
[pic]A power cord connected to a surge protector
The power cord is the link between the power outlet and the power supply unit in the computer casing. If the power cord is not plugged in, the computer will not power on. To protect your computer from voltage spikes, you can plug the power cord into a surge protector. You can also use an Uninterruptible Power Supply (UPS), which acts as a surge protector and also provides temporary power if there is a blackout.
i. System Unit: is the central component of a computer where all the processing takes place. The system unit consists of the computer memory, microprocessor and storage devices of the computer, other options like monitor, keyboard and mouse are all connected to the system unit.
ii. Display Screen/Monitor: is used to view the result of your request.
A monitor displays information in visual form, using text and graphics. The portion of the monitor that displays the information is called the screen. Like a television screen, a computer screen can show still or moving pictures.
There are two basic types of monitors: CRT (Cathode Ray Tube) monitors and LCD (Liquid Crystal Display) . Both produce sharp images, but LCD monitors have the advantage of being much thinner and lighter and more expensive, while CRT monitors are generally more affordable.
iii. Keyboard:- is used to enter information into the computer. It is just one of the input devices. Keyboard has five functional areas:- • Typing keys: most of the typing keys in the typing area function in the same way as on the typewriter. • Computer keys:- serve different roles with the program used. E.g. pressing F10 in one program may store your data, in another it may display a graph. • Dedicated cursor keys: is used to move the cursor arrow in the screen and through your data. Numeric keyboard serves two purposes:-. cursor movement and numeric data entry It also has a 3 indicator light points for Num Lock, Caps Lock and Scroll Lock. The status of each is shown by the glowing light.
iv. Mouse: - is a hand-handling computer components used in running parts of programme after clicking on them appropriately. It has three main portions right/left button, handling and scroller (roller). Three types are available serial, optical and cordless...
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