Earth's rotation and the gravitational pull of the sun and moon create tides on our planet. Because the sun is so much larger than the moon (27 million times more masssive), it has a much bigger graviational pull on Earth. The sun's extreme mass, and therefore gravitational pull, is why Earth (and the other planets and celestial bodies in the solar system) orbit the star. 

But tidal force's dependance on gravity can be a bit deceiving. Unlike gravity, tidal forces are much more dependant on distance than mass. So, the relatively small moon exerts a much stronger tidal force on Earth than the gargantuan sun because it is so much closer—on average the moon is 384,399.9 kilometers (238,855 miles) from Earth, while the sun is 149.6 million kilometers (92.92 million miles) away.

Earth's oceans, other bodies of water, and to a much lesser extent land respond to the moon by bulging and dipping as the moon revolves around Earth. The sun also plays a role in the formation of tides, but a much smaller one. Tides move around Earth as bulges in the ocean. As the ocean bulges toward the moon, a high tide is created. The high tide on the side of Earth facing the moon is called the high high tide. The high tide caused by the bulge on the opposite side of Earth is called the low high tide. (A low high tide may be understood as the moon's tidal force pulling the planet—not the ocean—toward it.)

Noun

our planet, the third from the Sun. The Earth is the only place in the known universe that supports life.

exert
Verb

to force or pressure.

gravitational pull
Noun

physical attraction between two massive objects.

high high tide
Noun

tide created when the Earth directly faces the moon.

high tide
Noun

water level that has risen as a result of the moon's gravitational pull on the Earth.

low high tide
Noun

tide created when the Earth faces away from the moon.

Moon
Noun

Earth's only natural satellite.

Noun

large body of salt water that covers most of the Earth.

Noun

large, spherical celestial body that regularly rotates around a star.

revolve
Verb

to orbit or spin around something.

rotate
Verb

to turn around a center point or axis.

Noun

object's complete turn around its own axis.

Noun

star at the center of our solar system.

tidal force
Noun

gravitational pull exerted by one object, such as the sun or moon, that raises tides on another object, such as the Earth.

Noun

rise and fall of the ocean's waters, caused by the gravitational pull of the moon and sun.