So, What Exactly Is Tide?
Tide is the name given to the periodic rise and fall of sea levels in a given place. This changing of sea level is caused by the combined gravitational forces of the Moon and the Sun, as well as Earth's rotation. In most places, there are two tides a day: high tide, when sea level is at its highest, and low tide, when the sea level is at its lowest. The area of seashore that is underwater at high tide (and exposed during low tide) is known as the intertidal zone.