Central Processing Units (CPUs) are the primary components of a computer that perform most of the processing inside a computer. They execute instructions from programs, manage data, and control other hardware components. The CPU is often referred to as the 'brain' of the computer, as it carries out the essential tasks that allow software to function. Modern CPUs are designed with multiple cores, enabling them to perform several tasks simultaneously, which enhances overall performance. They are crucial for running applications, games, and operating systems, making them a vital part of both personal computers and servers. Advances in CPU technology continue to drive improvements in speed and efficiency.