4. Random Access Memory (RAM)

How many times have you worked for a whole lesson on something which you were just about to save but then the computer crashed or your mate 'accidentally' switched it off. When you rebooted and logged back in, your work was gone forever.

This was because your work was stored in RAM, or 'temporary memory'. It was fairly safe there while the computer was working, but as soon as it was switched off, everything disappeared. This type of memory known as 'volatile memory'.

As well as storing the data you are working on, RAM also stores the modules that are needed to make your applications work. For example, when you open up Microsoft Word, you may notice a short delay while the modules are loaded into RAM.

RAM is also needed so that you can have multiple windows open and so that you can switch between them.

However, if you have a lot of windows, documents and different applications running, you might find that your system starts to slow down. This is because your RAM is full up and it is having to decide what it needs to keep stored in memory at any given time and what it can release. If this happens to you a lot, you can improve the performance of your computer by installing extra RAM.

Most computers are typically sold with 1-2 Gb of RAM installed. They sit on a slim circuit board shown above. These slot vertically into the motherboard.