Which component acts as the brain of the computer?

The central processing unit (CPU) is often referred to as the brain of the computer because it is responsible for executing instructions and processing data. It performs all the calculations, makes logical decisions, and manages the flow of information between the various components of the computer. The CPU interprets and performs commands from the computer's software, coordinating input and output activities, which are essential for the overall functionality of the system.

In contrast, while the power supply unit provides the necessary electrical power for the computer to operate, it does not manage or process information. The graphics card, primarily responsible for rendering images and video, handles specific graphics-related tasks but does not control overall operations. The hard drive, which is used for data storage, keeps information long-term but does not play a role in processing that information during operation. Together, these components support the CPU, but it is the CPU that truly drives the computer's functionality and operations.