Ocean tide
Ocean tides are due to the gravitational attraction between the Earth, the Sun and the Moon.
Influence of the Moon
Due to the effect of the Earth's rotation, water tends to escape its gravitational attraction by inertia. This trend is constant at all points on the surface.
The force of gravitational attraction that the Moon exerts on the Earth is greater in the zone of the Earth's surface closest to the satellite and less in the most distant. For this reason, at these two points on Earth, the water experiences elevations: in the first, towards the Moon, and in the second, moving away from it. This is how high tides originate.
During one rotation of the Earth on itself, that is, one day, all the points on the surface will be located once in the closest position and in the furthest away from the Moon, with which, all the waters they will experience throughout a day in two intermediate positions, during which the low tides will occur.
Influence of the Sun
The influence of the Sun on the tides is less, because although its size is much larger than that of the moon, it is further from the Earth than the satellite.