Final answer:
Alternating current (AC) is the type of current that reverses its direction periodically, in contrast to direct current (DC) that flows in a single direction.
Step-by-step explanation:
The type of current that travels in one direction for a period of time and then reverses its direction for a period of time is known as alternating current (AC). Unlike direct current (DC), which flows continuously in only one direction, AC periodically changes direction. This behavior is typical of the current that we receive in our homes and businesses, where the voltage source varies periodically, often sinusoidally. In contrast, devices like cars typically use DC, where the source voltage is constant.