Summary

The CPU (Central Processing Unit) is the brain of a computer. It processes instructions, performs calculations, and manages data. The CPU's clock speed measures how fast it can execute tasks, while the number of cores determines its multitasking ability. 

Cache memory stores frequently used data for quick access, enhancing performance. The instruction set dictates the types of tasks the CPU can handle. 

The fetch-decode-execute cycle explains how it retrieves and executes instructions. CPU performance can be improved by overclocking, though it may increase heat and power consumption.