For now, let's just think about, or at least look at, what a differential equation actually is. So if I were to write, so here's an example of a differential equation. If I were to write that the second derivative of y plus two times the first derivative of y is equal to three times y, this right over here is a differential equation. Another way we could write it, if we said that y is a function of x, we could write this in function notation. We could write the second derivative of our function with respect to x plus two times the first derivative of our function is equal to three times our function. Or if we wanted to use the Leibniz notation, we could also write, we could also write the second derivative of y with respect to x plus two times the first derivative of y with respect to x is equal to three times y. All three of these, I guess, equations are really representing the same thing.