https://medium.com/@orcadmarketing/a-tale-of-two-currents-ac-vs-dc-e424d93aa2a1 > Difference Between Alternating Current (AC) and Direct Current (DC) > Ever wonder why you need a wall adapter to charge your phone while your toaster plugs directly into the wall? The answer lies in the difference between alternating current (AC) that’s supplied to your house, and direct current (DC) that’s required to power an electronic device. Understanding the difference between AC and DC is important for anyone looking to build their own digital electronic devices.