Capacitance is physically defined as the ratio of stored charge on two electrodes to the voltage between them.
\(C = Q/V\)This is a very broad definition and it can apply to any two objects though typically it is reserved for conductive ones.
All objects have a capacitance to all other objects in the vicinity. This makes capacitance very difficult to measure or control in any general way.
An electronic component designed to maximize its capacitance is called a capacitor, however all devices have intrinsic capacitance.