Electrical polarity

Electrical polarity (positive and negative) is term use to describe the direction of current flow in an electrical circuit. Current flows from the positive pole to the negative pole. (electrons flows from negative to positive: http://amasci.com/amateur/elecdir.html, the difference in direction is due primarily to the discovery of electrical current before the discovery of the electron). In a direct current (DC) circuit, one pole is always negative, the other pole is always positive and the electrons flow in one direction only. In an alternating current (AC) circuit the two poles alternate between negative and positive and the direction of the electron flow reverses periodically.