In mathematics, a toroid is a surface of revolution with a hole in the middle, like a doughnut, forming a solid body.A toroid is a endless solenoid in form of a ring.The axis of revolution passes through the hole and so does not intersect the surface. For example, when a rectangle is rotated around an axis parallel to one of its edges, then a hollow rectangle-section ring is produced. If the revolved figure is a circle, then the object is called a torus.
