The movement of electrons inside an electrical conductor is called electric current. When the electrons oscillate back and forth, then it is known as alternating current.
Alternating current (AC) is produced in AC generators. The process takes place when a coil rotates in the presence of a magnet and the electrons move back and force inside the wire in the coil (see generator).

The electrons do not move along the conductor but oscillate around a fixed point.
The electromagnetic field created by the oscillating electrons moves along the conductor at the speed of light (c= 3·10 8 m/s) and the electrical signal moves along at the same speed.

The intensity of an alternating current is caused by the number of electrons that oscillate at every point on the conductor. It is measured by quantifying the charge (in coulombs) that goes through the cross-section in a second, and its unit is the ampere..