The difference between spring and neap tides is that spring tides are much higher than normal and neap tides are lower than normal. Spring tides occur because of the combined effects of the sun and moon, whereas neap tides happen when the sun and the moon are at right angles.
Spring tides are exceptionally high tides because the sun, moon and Earth are aligned, and this causes the gravitational pulls of the sun and moon on the Earth to be greatly multiplied. Earth experiences spring tides only during new and full moons. Because the sun and moon are at right angles together during a neap tide, the gravitational pulls partially cancel each other. The result is a very weak tide. Neap tides occur only during quarter moons.