When the sun and the moon are in line with each other, they pull the ocean’s surface in the same direction. This causes higher high tides and lower low tides. These tides are known as ‘spring tides’, although they have nothing to do with the spring season! Instead, there are spring tides during a new moon and a full moon.
At other times, when the sun and the moon are at right angles to each other they pull in opposite directions. When this happens, there are lower high tides and higher low tides than usual. These are called ‘neap tides’ and happen when there is quarter moon.