Introduction to Electronics: Terminology

This article contains the terms that we will often encounter in the succeeding lessons in Electronics.

AC and DC

Electricity flows in two ways, either in alternating current (AC) or in direct current (DC). The difference between AC and DC has to do with the direction in which the electrons flow.

In DC, the electrons flow steadily in a single direction, or "forward." In AC, electrons keep switching directions, sometimes going "forwards" and then going "backwards." DC is the kind of electricity generated by a battery. On the other hand, the power that comes from wall outlets is AC.

AC can even be changed to DC by an adapter, such as that used to power the battery on a laptop.
Source: Wise Geek