How does a power supply function in a computer?

In a computer system, the power supply unit (PSU) plays a crucial role by providing the necessary electrical power for all components to operate. This includes the motherboard, CPU, graphics card, storage devices, and any peripheral devices. The power supply converts electrical energy from an outlet into the low-voltage DC power that computer components require.

The power supply not only supplies the primary power but also ensures that the voltage levels remain stable to prevent fluctuations that could damage sensitive components. Various connectors and voltage outputs allow the power supply to cater to multiple components, ensuring that each receives the appropriate power needed for efficient and safe operation.

The other functions mentioned in the choices either pertain to different components within the computer or role functions that do not describe the power supply's primary objective. Therefore, the option focusing on providing power to the computer accurately captures the essential function of the power supply unit.