The force of the moon causes the rise and fall in the tides. Due to the fact that some parts of the Earth are closer to the moon than others and the gravitational force drops off, they experience a larger gravitational tug from the moon than parts farther away causing a higher tide to occur there. The Earth's 24 hour rotation causes the daily change in tides. The moon's gravity pulls on the Earth's oceans.
High tide aligns with the moon as Earth spins underneath.
Another high tide will occur on the opposite side of the planet at that exact time because gravity pulls Earth toward the moon more than it pulls the water. The sun's gravity has a similar but smaller effect on the tides causing the low tides. They occur when the moon and sun are perfectly aligned at 90 degree angles. They occur twice every month. This causes spring tides, which is the opposite of a neap tide.