Neap or ebb is a term used to describe the two types of tides. Neap tides occur when the sun and moon are at right angles to each other, resulting in lower than average tidal ranges. Ebb tides occur when the sun and moon are aligned, resulting in higher than average tidal ranges. The term 'TIDE' (4 letters) is used to describe the regular rise and fall of the ocean's surface caused by the gravitational pull of the moon and sun.