What is Direct Current?
In a DC (direct current) circuit, all the electrons hop from electron to electron in a single direction, hence the name, direct current. Since electrons only flow in one direction, electrical polarity matters, so you’ll need to place each wire exactly how it’s depicted on a wiring diagram.
Electrons flow from negative to positive. Since one side of the power source is always negative, and the positive side is always positive, the difference is what pushes electrons from one side to the other.
A battery in a flashlight is an example of a source of direct current.