Before explaining how the Moon does this, first letís define what tides are. Ocean tides are the regular rise and fall of waters as Earth experiences gravitational pull by other members of our solar system. Gravitational pull is merely the attraction of matter to other matter. Ocean tides are the consistent rise and fall of the waters as Earth feels the gravitational pull. High tide is when the ocean swells to its highest point which occurs approximately every thirteen hours. Low tide, therefore, is when waters sink to their lowest level. The Sun, the Moon and the planets all pull on the waters and land of the Earth. The sun exerts a strong gravitational pull on the Earth even though it is very far away (93 million miles) because it is so massive. The Moon also exerts a noticeable pull on the Earth. Thus even though it is small, (one eighty-first the mass of the Earth) it exerts a noticeable pull because it is so close.
The moon creates the tidal forces on Earth because it is closer and its gravitational pull varies distinctly from one place to another on our planet. The water that is presently under the face of the Moon is more strongly attracted to it since it is closer than the water on the other side of the Earth. But, both sides of the Earth experience high tide at approximately the same time. The reason for this is that the water on the face of the Earth closest to the moon tends to be pulled away from the Earth while the face of the Earth farthest from the moon is pulled away from the water that is there.