Tidal forces refer to the gravitational forces exerted by celestial bodies, such as moons or planets, on one another. These forces cause the deformation or stretching of an object, and are responsible for phenomena such as ocean tides on Earth. Tidal forces are also important in shaping planetary bodies and can have significant effects on the rotation and orbit of objects in space. Studying tidal forces is crucial for understanding the dynamics of celestial bodies and their interactions with one another.