Title: Identify the main parts of a computer
Course: Module 1, Concepts of Information and Communication Technology (ICT)

What are the main parts of a computer?

Computers are made up of many components. Many of these are internal, situated inside the computer case, and some are external, and generally called peripherals.

Let's look at some of the main parts of a computer...

Central Processing Unit

- The Central Processing Unit, or 'CPU' (or microprocessor) is the part of the computer that actually manipulates the data. An Intel Pentium 4 or an AMD Athlon is an example of a CPU.

- The speed at which a CPU runs is measured in MegaHertz (MHz) for older PCs or GigaHertz (GHz) for more modern PCs. The microprocessor speed is one of the main influences on the computer's performance.

Motherboard

- A motherboard is the central component of the computer. All the other devices are connected to it and it acts as an interface (link) between them.

Types of memory

- The two main types of memory are Read-Only Memory (ROM) and Random Access Memory (RAM).

- ROM holds permanent information such as the software that enables the components in your computer to communicate. It cannot usually be deleted or overwritten.

- RAM is a temporary memory store. It holds the data that is being manipulated by the CPU until it is moved to a permanent memory store such as a disk, or until the computer is switched off, when it is lost. For example, when you create a document it is stored in your computer’s RAM until you save it to disk.

Hard disk

- The hard disk is a device fixed inside the computer that stores large volumes of data which can be accessed and retrieved quickly.

- It is both an input and output device as information can be transferred to and from it. Hard disks can store far more data than floppy disks, CD-ROMs, or DVDs.

Graphics card

- The graphics card is the part of the computer directly connected to the monitor. It sends a signal to the monitor to control what it displays.

- Graphics cards nowadays commonly have dedicated processors for 3D graphics e.g. Games and CAD, and dedicated video RAM for large and complex images.

- Laptop computers always have a graphics card integrated with the motherboard. Entry level desktop computers usually have a graphics card built-in to the motherboard also. In high-quality desktop computers the graphics card is often separate, and can therefore be updated.

Keyboard

- The keyboard is an input device for text-based information.

- In addition to the QWERTY key layout, keyboards feature Function Keys such as [F1]-[F12] which perform specific tasks for some software. In many applications, for example, [F1] displays the Help screen.

Monitors

- The monitor is an output device. It is a screen that presents visual information about the computer’s activity.

- There are two main types of monitors — CRT and TFT.

- CRT monitors usually have a screen size between 14" and 24" but other sizes are available. TFT monitors have perfect picture geometry but are more expensive than CRT monitors.

- Recently LCD monitors have dramatically reduced in price, meaning 19" or 21" sizes are common.

Mice

- The mouse is an input device. It is used to point at objects such as menus, which it then activates when the mouse button (usually the left one) is clicked.

- If you are familiar with Microsoft Windows, Mac OS, or Linux you should be familiar with your mouse!

- Modern mice can be bluetooth or wireless - meaning there is no cord to attach.

- Some mice are 'optical' - they do not have a ball underneath to track movement, but use a small optical sensor.

Printers

- Printers are a common output device, and are used to create a 'hard copy' for distribution or filing.

- Although print outs are useful, many people try and keep documents in electronic format and not print them, partly for environmental reasons, and partly to ensure 'out of date' printouts are avoided.

- The wide-spread use of email means documents can be sent and received electronically instead of printing and posting.

Input output question

Which of the following is an input or output device?

- Mouse
- RAM memory
- CPU
- Motherboard