Which type of current flows in only one direction?

Direct current (DC) is characterized by the flow of electric charge in a single direction. This consistent flow allows for a stable voltage output, which is essential for many electronic devices and systems. In contrast, alternating current (AC) periodically reverses direction, which can result in voltage changes over time. Pulsating current refers to a type of DC that fluctuates in amplitude, rather than maintaining a steady flow, and variable current suggests changes in both voltage and direction. Understanding these distinctions is crucial for selecting the appropriate type of current for various applications in electrical systems.