Cycle

In alternating current, the current goes from zero potential or voltage to a maximum in one direction, back to zero, and then to a maximum potential or voltage in the other direction. The number of complete cycles per second determines the current frequency; in the U.S. the standard for alternating current is 60 cycles.

1. In pathfinding, a cycle is a path or tour beginning and ending at the same node.
2. In tracing, a cycle is a set of arcs forming a closed polygon. Upstream and downstream directionality are undefinable in a cycle.