The primary cause of high tides on Earth is the gravitational pull of the Moon. The gravitational force of the Moon pulls the water towards it, causing a bulge in the ocean that results in high tides. Additionally, the gravitational pull of the Sun also plays a role in the formation of tides, but to a lesser extent compared to the Moon. When the gravitational pull of the Moon and Sun align, it results in the formation of even higher tides, known as spring tides.
