What is the difference between AC and DC?

The distinction between AC (Alternating Current) and DC (Direct Current) primarily lies in the direction in which the current flows. AC is characterized by a current that reverses direction periodically, meaning it oscillates back and forth. This is commonly observed in power systems such as those providing electricity to homes and businesses, where the voltage alternates in polarity.

In contrast, DC flows in only one direction, maintaining a constant polarity, which is typical for batteries and devices powered directly by them. This fundamental difference in flow direction is pivotal in understanding their applications and how electrical systems function.

This understanding of AC alternating direction and DC maintaining a constant flow in one direction emphasizes their use in various types of equipment and infrastructure, clarifying why AC is typically associated with power grids and DC with portable electronic devices.