Understanding the different types of electric potential energy

Question

I have a paper on electric potential energy, it should be noted that the topic was not in anyway explained back when we were on campus so whatever little understanding i have of the topic right now is the result of relentless googling for a week or so, the wiki page divides electric potential energy into two sections:

1. Electrostatic potential energy of one point charge
2. Electrostatic potential energy stored in a system of point charges

my question is...what's the difference?
what's the difference between E.P.E of one point charge q in the presence of another charge Q and the E.P.E stored in a system of two charges? and why are their mathematical formulas different?

if someone could explain to me the classification that wikipedia has and provide me with resources that explain E.P.E in depth so i can use them in my paper i would be very grateful.

https://en.wikipedia.org/wiki/Electric_potential_energy

Answer 1

The two forms of potential energies are actually the same thing. The key point is the fact that, since Maxwell's equations are linear, you can superpose the effects of every single charge to find the total energy of a system.