The CPU is a critical component to your computer system. Without it, you basically have a pile of (circuit) boards and screws and wires. CPU itself stands for Central Processing Unit. Many people wrongly refer to the entire computer case as the CPU, but that is...well, wrong. The Central Processing Unit is a small chip that sits socked into your motherboard inside your c

omputer's case. You won't actually be able to see it directly, though, even if you open the case, because it will be sandwiched between the motherboard and a heat sink and fan. A CPU is not very big, but it is extremely important to the running of your computer system, because it basically acts as the computer's brain. Everything that your computer does, the CPU must process – the majority of the data must go through it to make your computer function properly. In many modern machines, the video cards, sound cards and other components may also process data and instructions, like the CPU does, but the majority of the work is in the CPU's hands.

The faster the CPU, the better your computer will run. Processor speeds are classified in megahertz (MHz) and gigahertz (GHz). 1 GHz is roughly 1,000 MHz. When shopping for a CPU, you should look at the GHz rating and go for the highest you can afford, because the faster your CPU is, the better off you will be. Also check out the Bus Speed. 200 MHz is the current basic standard, but you can find higher and lower Bus Speeds on CPUs for sale, so keep an eye out. Also look for the Internal Cache. The Internal Cache is the memory that the CPU uses to hold recent data for quick access. The more, the better. Intel CPUs tend to have low Internal Caches, so while they perform well with some applications, anything that is more CPU intensive may cause your system to slow way down. Also, smaller sized chips tend to run cooler, which let them run faster more safely, so keep an eye out for that, too.

Since the CPU is the brain of your computer system, it is important to take good care of it, and make sure you choose one that is strong and fast enough to hold up against all of the things you want to run with it.