The MOS Technology 6502 is a tiny little brain that tells computers what to do. It's like a really small boss that can control all the other parts of the computer.
The 6502 is made up of tiny little parts called transistors and it's really good at counting and doing math. It can add, subtract, multiply, and divide numbers really fast.
When you type something into a computer, the 6502 helps turn those letters and numbers into little signals that computers use to understand what you want them to do.
The 6502 is also really important because it was used in a lot of old computer games from a long time ago, like Super Mario Bros. and Donkey Kong.
Even though there are faster and more powerful computer brains now, the 6502 is still really cool because it helped start the computer revolution and made it possible for us to do all kinds of fun things with computers.