The PSU or Power Supply Unit is what brings every component of a computer to life. As the name suggests, it relays power from the wall to the different components of a computer, depending on how much they require. There are a plethora of PSUs in the market in different price brackets with different efficiency ratings, more on that later. They can start at an expensive price and go up to thousands of dollars. But this also means there are multiple options to compare and choose from at every price point. This guide focuses on the budget segment with power supplies under $100.