Every 24 hours and 50 minutes, the Earth experiences two high tides and two low tides. High tides occur every 12 hours and 25 minutes. From high tide to low tide is a span of six hours and 12.5 minutes.
At high tide, water covers much of the shore; at low tide, the water recedes, and much of the shore lies bare.
Both the sun and moon pull at the Earth; however, the moon exerts a more powerful influence because it is much closer to the Earth. This is called the tidal force. The part of the Earth that faces the moon experiences high tide – as does the opposite side of the Earth away from the moon. The areas between the regions of high tide have low tides.