Probably the most important part of your computer is the processor, also known as the CPU (Central Processing Unit). The speed of the processor is represented by a number such as 1.2 GHz or 900 MHz (1 GHz = 1,000 MHz). The number presented is the amount of cycles the processor runs through in one second. The processor is a chip that does the bulk of the work in your computer.
Although the CPU may be the most important single component, it still needs the rest of the computer to function; without a power supply to run it or a graphic card to display what it's running, the CPU would be useless.
Generally the faster the CPU the better the performance of the computer, but also the more expensive it will be. If you purchase the best processor available at the time, it will last you for several years whilst technology catches up with it. Hardware technology far exceeds current software technology, so with the best CPU available, you will be able to operate all current Operating Systems (OS), as well as a many future ones.
One of the biggest price-point decisions you will face in buying a computer is which processor to opt for. Processor technology moves so fast that you'll find most months bring out a new CPU. This causes the price of older models to drop rapidly.
