High tide occurs on the side of the Earth that is opposite of the moon during orbit, while the side of the Earth closest to the moon experiences low tide. The gravitational pull of the Earth and moon causes high and low tide.
While the Earth is spinning on its axis, the centrifugal force keeps all water on the planet at an equal level. The moon's gravitational force disrupts the equal balance that the Earth's gravity creates, and this produces bulges of water on one side of the planet. As the Earth rotates on its axis, the side of the planet that is opposite the moon changes.