What is defined as a moving ridge on the surface of the water?

A moving ridge on the surface of the water is best defined as a wave. Waves are oscillations of water that move energy across the surface. They can be generated by wind, seismic activity, or other disturbances, and their shape typically manifests as a crest and trough. The movement and energy transfer associated with waves are key characteristics that differentiate them from other water phenomena, such as currents, which involve the movement of water in a specific direction and are not restricted to surface ridges.

Ripples, while they can also be considered small waves, tend to refer specifically to lighter, smaller oscillations on the surface, typically caused by a small disturbance and lacking the larger energy and organized structure of waves. Swells are a specific type of wave that has moved far from its point of generation, often resulting in smooth and regular oscillations of the surface. Thus, the characteristics of a moving ridge align most directly with the definition of a wave.