Waves are oscillatory movement in water, manifested by an alternate rise and fall of the sea surface. Every wave has a wavelength, velocity, height and wave period. The rise and fall of sea water due to gravitational forces of the sun and the moon are called tides. The sea waves produced by tides are called tidal waves. Ocean currents are large masses of surface water that circulate in regular patterns around the ocean. It is of two types warm and the cold.
