During spring tides, the gravity of the sun and moon pull on the Earth either from the same direction or from opposite directions, producing higher tidal ranges. During neap tides, the sun and moon are at right angles with respect to Earth. This lessens their pull on Earth, producing lower tidal ranges.
As the earth and moon move, the moons gravitational force pulls on the ocean causing it to bulge off the surface of the earth but from our point of view it looks as if the water level is riding and lowering.
