Each of the sets forming a direct product is said to be a direct factor. A group G is said to be a direct factor of the group G' if G' is isomorphic to the group direct product G×H for some group H. In the case of Abelian groups, G×H is isomorphic to the direct sum G⊕H, and direct factor is a synonym for direct summand.

direct product | direct sum | direct summand | group direct product