I have to compare and contrast the difference between a service current and a wave.

These notes might help

*when the surface of the sea is distributed, waves are produced. waves are seen moving on the surface of water but actually their movement is not extensive and the movement of water from one part of the ocean to another gives rise to currents

*In alternating current (AC, also ac) the movement (or flow) of electric charge periodically reverses direction. In direct current (DC), the movement (or flow) of electric charge is only in one direction.