PSU

PSU The PSU (Power Supply Unit) is a square metal box, usually with a fan at the back, which is cabled to all the major components of a PC, particularly the motherboard, and provides the power for the PC to function. The power cord from the wall usually plugs straight into the back of the PSU directly, as it draws the appropriate power and regulates the precise voltages that certain devices need to function correctly. The PSU usually has a wattage rating which indicates the maximum power output of the PSU under load, with the more devices connected to a PC the higher the wattage required to maintain ample smooth power to each and hence keep the system stable under stress. In human body terms, the PSU is like the heart which pumps blood through the arteries and organs.  