In graph theory, the tensor product G × H of graphs G and H is a graph such that the vertex set of G × H is the Cartesian product V × V; and vertices and are adjacent in G × H if and only if g is adjacent to g' in G, and h is adjacent to h' in H.The tensor product is also called the direct product, Kronecker product, categorical product, cardinal product, relational product, weak direct product, or conjunction. Wikipedia