A processor is the part of a computer that does the actual thinking and calculating. Just as your brain processes information when you solve a math problem or decide what to say next, a computer's processor handles all its computational tasks: running programs, displaying graphics, playing music, and managing everything happening on screen.

The processor (also called a CPU, or “central processing unit”) executes billions of simple instructions every second. When you click to open a game, the processor interprets that click, loads the game's files from memory, calculates what should appear on screen, and coordinates with other computer components to make it all happen. Modern processors can handle multiple tasks simultaneously, which is why you can listen to music while writing a document while your computer checks for email in the background.

Processor speed is measured in gigahertz (GHz), which indicates how many billions of cycles it can perform per second. A faster processor can handle more complex tasks more quickly, though speed isn't everything: processor design and efficiency matter too.

The word processor also appears in other contexts: a food processor chops and mixes ingredients, and when someone processes information, they think it through carefully. In each case, something raw gets transformed into something more useful.