What is the difference between the electrostatic potential energy of a charge immersed in an electrostatic field and the potential energy between two charges?

I'm not asking for the formulas nor for their derivation, but I'm asking for the link between the two concepts.

Is there a connection between the two? Are they the same thing expressed in different ways? What does change?

I mean, teh two expressions are quite different, one is the potential energy for a single body, the other is a potential energy between two bodies. Moreover, one is zero at no distance between two objects, the other is zero at infinity.

What is an intuitive explanation for this? What do these energies represent?

Could the same be applied to gravitational potential energy as well?

Thanks!