What is the function of a power supply unit?

The function of a power supply unit (PSU) is to convert the alternating current (AC) from the electrical outlet into direct current (DC) that is suitable for powering the internal components of a computer or electronic device. It provides a stable and regulated power supply to ensure the proper functioning of the components. The PSU also protects the system from power surges, voltage fluctuations, and electrical noise by filtering and regulating the incoming power. Additionally, it distributes the power to different components of the system, such as the motherboard, graphics card, hard drives, and peripherals, through various connectors and cables.