What is a key difference between DC and AC voltages?

The core distinction between DC (direct current) and AC (alternating current) voltages lies in their flow direction. DC is characterized by the flow of electric charge in a single, consistent direction. This unidirectional nature makes it ideal for applications where stable voltage is required, such as in batteries, electronic devices, and most consumer electronics.

On the other hand, AC is defined by the alternating flow of electric charge, where the direction of the current periodically reverses. This bidirectional flow allows AC to be more suitable for power distribution in electrical grids because it can be easily transformed to different voltage levels, making it efficient for long-distance transmission.

In contrast, while AC is generally utilized for distributing electricity in residential and commercial settings, DC plays a significant role in many electronic devices, including computers, where it often powers internal components after being converted from AC through power supplies. The assertion that AC is always used in computers is misleading. Although AC is encountered in electrical supply, the internal operations of computers primarily rely on DC. Therefore, distinguishing between the unidirectional flow of DC and the bidirectional flow of AC is key to understanding their respective applications and roles in electronic systems.