Torus knot is a special kind of knot that lies on the surface of an unknotted torus.
Similarly, a torus link is a link which lies on the surface of a torus in the same way.
Each torus knot is specified by a pair of coprime integers p and q. A torus link arises if p and q are not coprime.
A torus knot is trivial (equivalent to the unknot) if and only if either p or q is equal to 1 or −1.