But what makes it even more powerful is it's connected to the notion of a derivative, which is one of these beautiful things in mathematics. As we will see in the fundamental theorem of calculus, that integration, the notion of an integral, is closely, tied closely to the notion of a derivative. In fact, the notion of an antiderivative. In differential calculus, we looked at the problem of, hey, if I have some function, I can take its derivative and I can get the derivative of the function. Integral calculus, we're going to be doing a lot of, well, what if we start with a derivative, can we figure out through integration, can we figure out its antiderivative, or the function whose derivative it is? As we will see, all of these are related. The idea of the area under a curve, the idea of a limit of summing an infinite number of infinitely thin things, and the notion of an antiderivative, they all come together in our journey in integral calculus.