Capacitance

It is the ability of a device to store charge for a given applied potential difference.

A capacitor is a device that stores charge.

\(\large C=Q/V\)

For a parallel plate capacitor of plate area \(\large A\), spaced apart at a distance \(\large d\),

\(\large C=\dfrac{\epsilon A}{d}\), or

\(\large C=\dfrac{k \epsilon_0 A}{d}\), where \(\large k\) is the dielectric constant, or relative permittivity.