What is a defining characteristic of direct current (DC)?

Direct current (DC) is defined by its consistent flow of electric charge in a single direction. This characteristic distinguishes it from alternating current (AC), which periodically reverses its direction of flow. The unidirectional flow of DC makes it particularly well-suited for applications such as battery-powered devices, electronic circuits, and certain types of motors.

In contrast, other options suggest flowing in both directions, which describes AC, or imply that DC must involve a generator, which isn't necessary since DC can also be produced by other means, such as batteries. The notion that DC is inherently more dangerous than AC is not accurate because the danger posed by either type of current depends on various factors, including voltage and exposure risk. Thus, the defining characteristic of DC is its flow in only one direction, which is essential for understanding the behavior of electrical systems that utilize this form of current.