The CPU, or Central Processing Unit, is often referred to as the brain of a computer. It performs calculations and executes instructions that allow software applications to run. The CPU processes data by using its cores, which can handle multiple tasks simultaneously, improving overall performance. Inside the CPU, there are several components, including the ALU (Arithmetic Logic Unit) for mathematical operations and the CU (Control Unit) that directs the flow of data. The speed of a CPU is measured in gigahertz (GHz), indicating how many cycles it can perform per second, which affects how quickly a computer can operate.