The seas’ water rises (high tide) and falls (low tide) depending on the pull of the moon and the sun on the flow of the oceans’ water.
The moon tries to pull at anything on the Earth to bring it closer. But, the Earth is able to hold onto everything except the water. Each day, there are two high tides and two low tides. The ocean is constantly moving from high tide to low tide, and then back to high tide. There are about 12 hours and 25 minutes between the two high tides. As the moon travels around the earth and as they travel together around the sun, the combined gravitational forces cause the world's oceans to rise and fall.