What is the primary purpose of a power supply unit in a computer?

The primary purpose of a power supply unit (PSU) in a computer is to convert alternating current (AC) from a wall outlet into direct current (DC) that the computer's components require to function properly. Most internal components of a computer, such as the motherboard, processors, and storage devices, operate on low-voltage DC power. The power supply unit ensures that the appropriate voltage and current levels are delivered to each component, allowing the computer to operate efficiently and effectively.

While increasing memory capacity, managing data storage, and providing cooling are essential functions within a computer system, they fall under different categories of hardware components. For instance, memory capacity is increased through the installation of additional RAM modules, data storage management is handled by hard drives or SSDs, and cooling systems consist of fans and heat sinks. The PSU's unique role is focused solely on power conversion and distribution.