What is a computer?
A computer is made up of lots of different components connected together. Anything we can touch with our hand relating to computers we call 'hardware' so a computer is made up of lots of different pieces of hardware. Once connected together, they won't work unless we give the hardware some instructions, called programs. Programs are known as 'software' and it is the programs that make the hardware actually do useful things. One very important piece of software for computers is called the 'operating system' or OS. This is the program that controls all of the hardware to make them work together as a computer system. We will learn more about this in another section.
If we looked inside and outside of any computer at the different pieces of hardware, we would usually find most of the same components. Can you label the diagram with the correct letter to show what that component is?
Label | Description |
A | The motherboard. This piece of hardware is a printed circuit board, which allows all of the other components to be connected together so that they can communicate with each other as well as extra 'ports' - places you can plug something external into e.g. a printer or pen drive. USB ports are common types of port found in computers. |
B | The mouse and keyboard. These pieces of hardware allow a user to make selections and enter data into the computer. |
C | The Central Processing Unit (CPU). This piece of hardware is the brain of the computer. It does all of the calculations (or processing) and runs the programs. |
D | The hard disk. Your programs have to be stored somewhere, even when the power is off. They are all stored here, in the hard drive. |
E | These come in handy when you want to listen to music! |
F | The sound card. If you want to listen to some digital music, such as an MP3 file, then you need to output the file to some speakers. You will need a good quality sound card to enable you to do this. |
G | The CPU works very hard and can get hot. This fan sits right on top of the CPU and keeps it cool. |
H | The RAM (Random Access Memory). Those programs that you are currently running are copied from the hard drive to the RAM. The CPU then fetches and executes the instructions in each program in RAM to make the programs 'run'. If you turn the power off, all of the contents in RAM are wiped away, although they are all still safely stored in the hard drive. The more RAM a computer has, the more programs you can run efficiently on your computer. That's why buying more RAM for your computer is usually a good idea. RAM is also known as a 'Read-Write' piece of hardware because you can both read from it and write to it. |
I | A graphics card. You need a graphics card to send signals from your CPU to the monitor so you can actually see things! |
J | A network card. Most computers are connected to a network, for example, the Internet. To do this, you must have a network card in your computer. |
K | The case. You need to keep the motherboard and all of the other components safe. You also might need to attach other things to the motherboard, such as a DVD drive. The computer case provides a structure and a protective environment for all of the hardware. |
L | Monitor (also called a VDU - Visual Display Unit). You need this to see the signals as they come out of the graphics card. |
M |
The ROM (Read Only Memory). This is an electronic chip that contains the instructions a computer needs to 'boot up', the term used to describe when you first press the power switch to turn your computer on. It checks that your computer is okay and then loads up the OS from the hard drive to the RAM and starts running it. This chip is known as 'Read only' because you can never change the contents of it. |
Extension task
1) Write a list of anything else that you might connect to a computer. Compare your list to students' lists around you and see how large you can make your list.
2) Using the table above and anything else you can think of, compare a laptop to a desktop computer. Write down the ways they are similar and the ways that they are different.