The CPU

All you need to know about it

What does the CPU actually do?

A central processing unit (CPU) is an important part of almost every computer. The CPU sends signals to control the other parts of the computer, almost like how a brain controls a body.

The CPU is an electronic machine that works on a list of things to do, called 'instructions'. It reads the list of instructions and does (executes) each one in order. A list of instructions that a CPU can read is a computer program. A machine that can perform the job of a CPU is often called a Turing machine by mathematicians.

How do you measure the speed of the CPU?

The speed that a CPU works at is measured in hertz, Hz. Modern processors often run so fast that gigahertz, GHz, is used instead. One gigahertz is one billion hertz.