Electric current moves often like a water stream. The only difference here is that electric charges do not always move in the same direction. When they do, it is called Direct Current or DC.
On the other hand, AC or Alternating Current, as the name suggests, occurs when charge carriers in a conductor, or semi conductor, reverse their direction of movement in a periodic manner.
With AC, it is possible to run many types of electrical equipment like generators, motors, power distribution systems etc. and also kitchen appliances, TVs, electric lamps etc. Hence, for almost all high power applications, it is a global trend to use AC instead of DC because of its higher efficiency. Besides these advantages over DC, AC power is believed to be less expensive. One can also use high voltages with small currents to reduce losses, with AC power.
It was in the 1850s that the alternating current technology first surfaced in Europe. One of its pioneers is the French inventor Guillaume Duchenne.
