The Central Processing Unit (CPU) is the primary component of a computer that performs most of the processing inside a system. Often referred to as the "brain" of the computer, the CPU executes instructions from programs and performs calculations needed to carry out various tasks. It handles arithmetic, logic, control, and input/output operations, enabling the computer to run applications and respond to user commands. CPUs are typically composed of multiple cores that allow for multitasking and faster performance. Modern CPUs, like those from Intel and AMD, are designed for a range of devices, from desktops to smartphones.