The type of electricity that is delivered to your home that you plug your devices into at the wall socket is alternating current (AC) electricity. And it’s just like the name suggests: the current alternates its polarity. Computers, meanwhile, need Edison’s direct current (DC) electricity to operate. That’s where PC power supplies come in.
They work by changing the alternating current that comes out of your wall into the direct current your computer can safely use. PC power supplies come in several different wattages and the best PC power supply is one that is able to detect that correct voltage for your PC’s needs.