plotting - Difference between two Listplots

this is a simple question, and excuse me if it's already been answered; I searched around and couldn't find anything.

I have two listplots, both along the same number of x data points, but with different y values. I want to find the difference between the two y values, while keeping the x values the same. I tried just subtracting the two, but that leaves all the x values as equal to 0, which is undesirable, of course.