The tide is the greatest synchronized movement of matter on our planet. Every drop of seawater takes part in tidal motion, driven by the gravitational pull of the Moon and Sun. Tides: A Very Short Introduction blends clear explanations of well-known tidal phenomena with recent insights into the dynamics of the deep ocean and coastal seas, considering the tide’s nature and causes, its observation and prediction, and unusual tides and their relevance. It explains the importance of ocean tidal mixing as a key part of our planet’s climate-control system and for enhancing biological productivity. It also considers the effects of tidal processes beyond our own planet on the moons of Jupiter and Saturn.