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Alternating current (AC) is a type of electric current where the flow of electrons, or charge carriers, periodically changes direction. Unlike direct current (DC), where electrons flow in a single, constant direction, AC reverses its direction at regular intervals multiple times per second.
In simpler terms, during one cycle, the electrons move forward (→) for a short period and then backward (←) in the opposite direction. This continuous back-and-forth motion of electrons occurs repeatedly in a conducting wire, as illustrated in the figure above.
This unique behavior of AC is the foundation of how most power systems operate, ensuring efficient energy transmission over long distances. The frequency of these reversals depends on the power supply standards—50 Hz or 60 Hz being the most common worldwide.
