Question

What is the main cause of tides?

Answer 1

I'm not exactly sure on this one but please bare with me haha

High tides and low tides are caused by the moon and tides are really all about gravity(hence why all of these answers have gravitational in them). And, when we are talking about "daily tides" it's the moon that causes them.

The moon's gravity draws in various areas of our world as it rotates. Since the moon is just 1/100th the mass of the Earth, it has enough gravity to shift objects about. The ocean on the moon's far side is still trying to bulge out against it. A high tide is what we term this bulge. (Water is easy to move around too)

This is tidal force, and there are differences between high tides and low tides.