Rigid motion refers to a transformation in geometry that preserves the shape and size of a figure. This means that when a shape undergoes rigid motion, its dimensions and angles remain unchanged. Common types of rigid motion include translations, rotations, and reflections. In rigid motion, the original figure and its image after transformation are congruent, meaning they can be perfectly overlapped. Rigid motion is essential in various fields, including mathematics, physics, and computer graphics, as it helps in understanding symmetry and the properties of shapes.