CPU stands for Central Processing Unit, the brain of a computer. Just as your brain processes information and tells your body what to do, the CPU processes instructions and tells the computer what to do.

When you click a button, type a letter, or load a video game, the CPU is doing millions of calculations per second to make it happen. It takes instructions from programs, performs mathematical operations, and sends signals to other parts of the computer. A faster CPU can handle more instructions per second, which is why newer computers often feel quicker and smoother than older ones.

The CPU is a small chip packed with billions of tiny electronic switches called transistors. These switches turn on and off incredibly fast, creating the patterns of electricity that represent all the information your computer works with, including numbers, letters, images, and sounds.

You might hear people talk about processor speed, measured in gigahertz (GHz). A 3 GHz processor can perform about three billion operations every single second. While speed matters, modern CPUs also have multiple cores, which are like having several brains working together on different tasks at the same time. That's why a quad-core processor (one with four cores) can handle complex video editing or run multiple programs at once without slowing down.