Final answer:
Spring tides are the largest tides that occur when the Earth, Moon, and Sun are aligned, causing the gravitational forces of the Moon and Sun to reinforce each other. This alignment happens during the new or full moon phases, leading to higher high tides and lower low tides. Neap tides, the smallest tides, occur when the Sun and Moon are at a right angle to each other.
Step-by-step explanation:
Spring tides are the largest tides that occur when the gravitational forces of the Moon and the Sun combine. This phenomenon happens when the Earth, the Moon, and the Sun are aligned, either during the new moon or the full moon phase, resulting in the highest high tides and lowest low tides. The term "spring" refers to the idea that the tides seem to "spring up" higher than usual, not to the season of the year.
During these alignments, the tidal effects from the Sun and the Moon add together to create tidal bulges on both sides of the Earth, which is why spring tides are roughly the same whether the Sun and Moon are on the same or opposite sides of the Earth.
In contrast, the smallest tides, known as neap tides, occur when the Sun and Moon form a right angle relative to the Earth, diminishing the overall tidal effect.