For a parallel-plate capacitor, \(C\) depends only on the area \(A\) of the plates, the distance \(d\) between them, and the material between them. We’ve assumed that the plates are separated by vacuum; in Section 17-8 we’ll explore what happens if the space between the capacitor plates is filled with a different material. Capacitance is therefore a compact way to summarize the electrical properties of a capacitor. In particular, capacitance tells us the amount of charge that can be stored on a capacitor held at a given voltage.