Changes

Homotopy groups are tools used in [[algebraic topology]] to classify [[topological space]]s.  The different ways to map an '''n-sphere''' continuously into a given topological space are divided into equivalence classes, called '''homotopy classes'''.

Homotopy groups are tools used in [[algebraic topology]] to classify [[topological space]]s.  The different ways to map an '''n-sphere''' continuously into a given topological space are divided into equivalence classes, called '''homotopy classes'''.