What characterizes Direct Current (DC) as opposed to Alternating Current (AC)?

Direct Current (DC) is characterized by the flow of electric charge in a constant direction, which distinguishes it from Alternating Current (AC), where the direction of the current reverses periodically. In DC, the voltage remains constant over time, resulting in a steady flow of electrons. This property makes DC suitable for powering devices such as batteries and electronic circuits, which require a stable current without fluctuations.

AC, in contrast, alternates between positive and negative voltages, making it ideal for applications such as power distribution over long distances. Additionally, because DC flows in one direction, it eliminates issues related to phase shifts and allows for simpler circuit designs in many instances compared to AC circuits.

Thus, the defining characteristic of DC being that it flows in one direction is integral to understanding its applications in electronics and power systems.