CPU

A Central Processing Unit(CPU), is a computer component that does computation for the PC.

Due to its role, it can be seen as the brain of the computer.

Function

A CPU purpose is to compute things for the computer. It does this by following the set of instructions(look in architecture) detailed in a computer program.

In current times CPU are not just processing units but also handle other tasks. One such controller that has been moved onto the CPU is a memory controller.

Instruction Sets

A CPU follows commands which it uses to compute values. This is what is known as 'the ones and zeros' which a computer is processing. All programs get compiled into these instructions which the cpu executes. Note the Operating Systems are also programs and thus are just instructions as well.

The reason this is important is that you can only run programs that are compiled for your instruction set. The windows RT

The instruction set which Intel and AMD CPU use is called x86 and x86_64. You might see that on the end of some installer filenames.

Another common instruction set is ARM. This is the most popular smartphone cpus