So in the example we did, h was the difference between our two x values. This distance was h. And that gave us the point, the slope of that line. We said, hey, what if we take the limit as this point right here gets closer and closer to this point? If this point essentially almost becomes this point, then our slope is going to be the slope of our tangent line. And we define that as the derivative of our function. We said that's equal to f prime of x. So let's see if we can apply this in this video to maybe make things a little bit more concrete in your head.