In topology, cobordism classes are a way to categorize manifolds based on their boundaries. Two manifolds are considered cobordant if there exists a higher-dimensional manifold whose boundary is the disjoint union of the two manifolds. This concept helps in understanding the relationships between different manifolds and their properties. Cobordism classes form an equivalence relation, meaning that if one manifold is cobordant to another, they belong to the same class. This classification is important in fields like algebraic topology and can be used to study the properties of manifolds, such as their homotopy and homology groups.