Covers in the Canonical Grothendieck Topology

Abstract: We explore the canonical Grothendieck topology in some specific circumstances. First we use a description of the canonical topology to get a variant of Giraud's Theorem. Then we explore the canonical Grothendieck topology on the categories of sets and topological spaces; here we get a nice basis for the topology. Lastly, we look at the canonical Grothendieck topology on the category of $R$-modules.