The central processing unit (CPU) is often referred to as the brain of a computer. It performs calculations and executes instructions from programs, allowing the computer to function. The CPU processes data by using its cores, which can handle multiple tasks simultaneously, improving overall performance. CPUs are found in various devices, including personal computers, laptops, and smartphones. They work closely with other components, such as the random access memory (RAM) and motherboard, to ensure smooth operation. The speed and efficiency of a CPU are measured in gigahertz (GHz), indicating how many cycles it can perform per second.