The document discusses set operations including unions, intersections, differences of sets, and Cartesian products. Ordered pairs are used in Cartesian products where order matters, unlike sets where order does not. Cartesian products pair each element of one set with each element of another set. The cardinal number, or total number of elements, of a Cartesian product of two sets A and B is found by multiplying the cardinal numbers of each set, written as n(A) x n(B). Venn diagrams can be used to represent set operations visually.