Potential energy is energy associated with a system's configuration. For example, arrangements of charges can be more or less energetic, as in, you need to perf

Potential energy is energy associated with a system's configuration. For example, arrangements of charges can be more or less energetic, as in, you need to perform or can extract work when you go from one configuration to another. This is a rather abstract notion. However, as energy (or rather, stress-energy-momentum) is the source of gravity, you actually do need to know precisely where that energy is located if you want to do general relativity. In case of the example above, the energy will be stored in the electromagnetic field. The gravitational field itself is an exception to this: While it can be used to store energy, in the general case, it's impossible to locate it. I'd argue this is a consequence of general relativity's unification of gravity and inertia.