CPU
The computer's general-purpose chip, fast at one careful step after another.
See it in Cellular automata. Press Step: the next generation of the grid is worked out on the CPU.
In plain words
CPU stands for central processing unit, the main chip in a computer. It has a few powerful cores that can handle any kind of task. It is best at work that goes step by step, with choices along the way. Page code, file saving and game rules run on it. Heavy picture work usually moves to the GPU instead.