Before you ask, no, we're not talking about the band. We're talking about current. Specifically the current that runs through everyone's houses, and some interesting facts about it. For those who didn't already know, almost every household outlet provides alternating current to whatever is plugged into it, yet a lot of electronic devices, like phone chargers, take direct current. So why is AC used? Well, part of the reason is to make use of important devices called transformers. They're those buzzing metal boxes that are usually suspended from poles that hold up power lines or placed near larger buildings. Power plants generate higher voltage than what is used in homes for everyday appliances, so what a transformer does is convert it to a lower voltage. Inside the transformer are coils of wire. Current flows in and enters a coil with a lot of loops in it, inducing a magnetic field, and since it is alternating current, the magnetic field changes. This changing magnetic field is used to induce a current in another nearby coil with less loops. This induces a current in the smaller coil with less voltage. When you plug something like a phone charger into an outlet, that box where the plug is has another smaller transformer in it, along with a circuit set up to convert AC to DC with the proper voltage for what you need to use.