The document defines Cartesian products as the set of all ordered pairs (a,b) where a belongs to set A and b belongs to set B. It provides an example, finding the Cartesian product of sets A={a,b} and B={1,2,3}. The document also defines domain as the set of all possible x-values of a function, and range as the set of all possible y-values. It distinguishes between functions, where each x is assigned one y, and relations where x may be assigned multiple y's. Graphs are introduced as a way to show relationships between two sets of numbers on an x-y coordinate plane.