Plus a very short history lesson

What is a CPU? The CPU, or Central Processing Unit, is the mathematical brain of a computer. Everything a computer does, from playing video games to helping you write an essay, is broken down into a set of mathematical instructions. The CPU takes those instructions and executes them.

The details of how it does this are of course much more complicated than that simple explanation. The most important thing to know is that the CPU is the main mathematical engine of a computer.

The history of computers is long and complex. It also goes back further in history than digital technology, electronics or even electricity. An abacus is a type of processor. So are mechanical calculators. The big difference is that these machines can only perform one or a few mathematical tasks. They are not general-purpose processors, of which the modern CPU is an example.