This is the continuous flow of electrons through a conducting material such as a metal wire. In direct current the electron flow is always in the same direction.
Alternating Current (ac)
An alternating current is one which is constantly changing direction or alternates in direction. The back and forth motion occurs between 50 and 60 times per second, depending on the electrical system of the country.
Therefore, the difference between dc and ac is that dc is continuous and in one direction, whereas ac alternates in direction
