A torus is a three-dimensional geometric shape that resembles a doughnut. It is defined mathematically as the surface of revolution generated by rotating a circle around an axis that is coplanar with the circle but does not intersect it. The torus has a central hole, which distinguishes it from other shapes like spheres or cubes. In mathematics, the torus is often studied in topology, a branch that explores properties of space that are preserved under continuous transformations. The torus can also be found in various fields, including physics and computer graphics, where it serves as a model for complex structures and phenomena.