A power supply unit, commonly abbreviated as PSU, does more than just supply your computer with power. It is the point where power enters your system from an external power source and is then allocated by the motherboard to individual component hardware. Not all power supplies are made equally however, and without the right wattage PSU your system will fail to work. A modern computer will generally need a PSU that rated between 500W 850W to effectively power all hardware, although the size of the PSU will depend entirely on the power consumption of the system. Computers that are used for highly intensive tasks such as graphic design or gaming will require more powerful components and thus will need a bigger PSU to cater to this additional need. Without the right amount of power, components wont be able to run effectively and the computer might experience crashes or simply fail to boot at all. Its recommended to have a power supply that more than covers your system usage. Not only do you guard yourself against system failure, you also future-proof yourself against needing a new PSU when you upgrade to more powerful PC components. Understanding your computer and its hardware components can prove very useful when the time comes to upgrade or replace any parts, or when building a computer. Should a problem arise with the internal workings of your computer, you will have a better understanding of the importance of each component, the need for them to be in good working condition and how to go about solving any issues. A power supply unit, commonly abbreviated as PSU, does more than just supply your computer with power. It is the point where power enters your system from an external power source and is then allocated by the motherboard to individual component hardware. Not all power supplies are made equally however, and without the right wattage PSU your system will fail to work.