What does alternating current (AC) signify?

Alternating current (AC) indicates a flow of electric charge that periodically reverses direction. In an AC system, the voltage and current constantly change, oscillating back and forth. This characteristic is crucial in many applications, such as in household power supply systems and various electrical appliances that operate efficiently with alternating current. The periodic reversal of direction leads to a wave shape, commonly represented as a sine wave.

The unique properties of AC, such as being easily transformable to different voltages through transformers, make it ideal for long-distance transmission of power. Unlike direct current (DC), which flows in a single direction, or constant current, which remains steady over time, AC's ability to switch directions is essential for the function and efficiency of many electrical systems.