A computer power supply unit (PSU) is a hardware device that converts AC electricity into DC electricity and then distributes it to the rest of the computer. The PSU is one of the most important components in a computer, as it provides power to all of the other components, such as the CPU, motherboard, memory, storage, and graphics card.

Here are some of the key features of a computer PSU:

• Wattage: The wattage of a PSU is the amount of power that it can deliver to the computer's components. The wattage requirement of a computer will vary depending on the components that are installed. It is important to choose a PSU with a wattage rating that is high enough to meet the needs of the computer.
• Efficiency: The efficiency of a PSU is a measure of how much power it converts from AC to DC electricity without wasting any. A more efficient PSU will waste less power and generate less heat.
• Form factor: The form factor of a PSU is the size and shape of the unit. The most common form factor for PSUs is ATX.
• Voltage regulation: Voltage regulation is the ability of a PSU to maintain a constant voltage output, even when the input voltage fluctuates. Good voltage regulation is important for the stability of the computer.
• Protections: PSUs typically have a number of protections to prevent damage to the computer's components, such as over-voltage protection, over-current protection, and short-circuit protection.

In addition to these key features, some PSUs may also have other features, such as:

• Modular cables: Modular cables allow users to connect only the cables that they need, which can improve airflow and reduce cable clutter inside the computer case.
• RGB lighting: Some PSUs have RGB lighting, which can be used to enhance the appearance of the computer.
• Zero fan mode: Some PSUs have a zero fan mode, which means that the fan does not turn on until the PSU reaches a certain temperature. This can reduce noise and improve efficiency.