What is the primary difference between AC and DC power?

The distinction between AC (alternating current) and DC (direct current) power lies primarily in the direction of the flow of current. AC power alternates its direction of flow, meaning that the current changes its polarity periodically. This characteristic allows AC to be transmitted over long distances more efficiently and makes it suitable for residential and commercial power distribution systems.

In contrast, DC power flows in a single, constant direction. This unidirectional flow is commonly seen in batteries and electronic devices where a stable voltage is required. Understanding this difference is fundamental for anyone working with electrical systems, as it influences the design and functionality of electrical circuits and the choice of power sources for various applications.

Additionally, while other statements may imply varying aspects of performance or application, the core principle remains centered on how these two types of current behave.