A relation is similar to a function in the sense that it establishes a connection between two sets but it's "looser" in the sense that it doesn't have the requirement that every x value has to be matched with a single y value. As you'll see throughout this series, as useful as functions are, removing this requirements creates a class of objects that are just as interesting and useful. (lecture slides)

Now that we've got the definitions of a cartesian product and a relation to work from, we're going to take the next step and look at some examples of them. (lecture slides)

We need one more relation related definition before we can start talking about properties and applications. Fortunately, as you'll see, the inverse of a relation follows the exact same pattern that you've already seen for the inverse of a function. (lecture slides)