So that is, if we call this a y-axis, we could even call this y equals s of t as a reasonable way to graph our position as a function of time function. And now let's think about what happens if we want to think about the change in position between two times. Let's say between time a. Let's say that's time a right over there. And then this right over here is time b. So time b is right over here. So what would be the change in position between time a and between time b?