Topology is the study of the properties of space preserved under continuous deformations, including twisting and stretching. Topology originated from the study of geometry and set theory and has many branches today. Wolfram|Alpha has the knowledge and ability to handle multiple topological topics, like computing the homotopy groups of an n-sphere (algebraic topology) or visualizing a knot (geometric topology).
Compute properties for one real interval or compare multiple intervals.
Compute the homotopy groups of an n-sphere.
Find and visualize knots, either by specifying a common name or using knot notation.