How does AC power differ from DC power?

AC (alternating current) power differs from DC (direct current) power primarily in the direction of flow. AC constantly changes direction, cycling through a waveform that typically alternates between positive and negative values. This periodic reversal is what characterizes AC, making it suitable for power distribution systems, as it can be easily transformed to different voltage levels using transformers. The periodic nature of AC is beneficial for electrical grid stability and is widely used in homes and industries for various applications.

In contrast, DC power flows in a single, constant direction. This steady flow is characteristic of batteries and electronic devices that rely on a stable voltage supply. While DC has its own applications, especially in electronics and components that require a consistent voltage, it is not suitable for long-distance power transmission as efficiently as AC.

The other options, while related to AC and DC power, do not address the fundamental difference as effectively. Safety and voltage levels can vary based on the specific application and design systems, rather than being inherent differences between AC and DC. Hence, the distinction in directionality is critical for understanding how these two types of power operate and are utilized in electrical systems.