Hard Disk
Often referred to as the HDD or Hard Disk Drive. Every time you save something on your computer or install a new program it is saved on the Hard disk. All this data is stored magnetically, which means it is not lost when the computer is turned off. This is the main distinction with RAM which is reset every time the computer is turned off.

Modem
Short for modulator/demodulator. A modem will convert digital signals into analogue signals and therefore allow the computer to access the Internet through an ordinary phone line.

Motherboard
This is the main circuit board in the whole computer; it connects and re-directs all of the internal and external hardware, and is also the housing place for the Processor. It carries information between the various parts as the information is processed.

Power Supply
This generally comes with the case of the computer and is used to convert the Power from the socket which is AC (Alternating current) to DC (Direct Current) which the computer requires to operate. It provides a steady stem of power for the computer.

Memory
More commonly know as RAM or Random Access Memory. It enables a computer to store data and programs temporarily. The more memory you have, the more programs you can have running simultaneously and the more data can be held for faster access by your machine. Memory does not "remember" your data. Memory is dynamic, so when the computer is switched off all of the data that was in the RAM at the time will disappear.

CPU
The Central Processing Unit or the “brains” of the computer is more commonly referred to as the CPU. Basically the CPU is a sort of chip that runs everything in the computer; it directs and re-directs everything that goes on in the computer. CPU’s come in various speeds and levels of power. This is the processing power, which is the speed that it can conduct all of the procedures, and it is measured in GHz (Giga Hertz)