ABSTRACT
We now introduce the primary object of interest in this book: the idea of a graph product. Broadly speaking, a graph product is a binary operation on Γ or Γ0. However, under reasonable and natural restrictions (such as associativity), the number of different products is actually quite limited. The chapter begins with definitions of three main products that have been studied in the literature: the Cartesian product, the direct product, and the strong product. We then treat the issue of associativity (which allows for the easy extension of these products to arbitrarily many factors) and we examine the projections of products to their factors.
