👉 In algebraic topology, a cohomology class is an element of the cohomological space. A cohomology class in a topological space X is defined as a map from the set of all neighborhoods of 0 in X to the integers Z, such that certain properties are satisfied. For example, if X is a topological space and f: XY is a continuous function between two spaces Y and Z, then the cohomology class [f] ∈ H^k(X,Z
