Due to its force of gravitation, the moon pulls certain parts of the Earth closer to it more strongly, creating the tidal bulge in the oceans of our planet. Since the Earth rotates much faster than the moon, this bulge occurs slightly ahead of the latter, which, due to a number of physical phenomena, pushes the moon into a higher orbit around Earth.
It's dangerously easy to take the moon for granted. The same thing is true for the sun. However, if it weren't for their eternal presence in our skies, life on Earth would be very, very different from what it is now, and it wouldn't be a particularly pleasant thing for us!
However, our only natural satellite – the moon – is actually moving away from Earth. Its orbit is getting larger every year!