So this is that thing. And then this thing right here is just the function evaluated at the point in question, right there. So this is our change in y. And let's divide that by our change in x. If this is x plus h and this is just x, our change in x is just going to be h. So that's where we get that term from. So this is just a slope between these two points. But of course, we want to find the limit as this point gets closer and closer to this point, as this point gets closer and closer to that point.