Is voltage just the energy created from the separation of charges?

Yes indeed.

• Electric potential energy $U_e$ is the potential energy stored when charges are out of equilibrium (like gravitational potential energy when an object is lifted above the ground).

• Electric potential is the same, but per charge, $frac{U_e}q$. (Useful when comparing different points.)

• An electric potential difference between two points is called voltage, $V=frac{U_{e2} }q-frac{U_{e1}} q$.

Voltage is a measure of the tendency of charges to move. If a charge is alone, then it has no tendency to move at all (there is no electric force pushing or pulling). If two charges are together, then their electric forces create a potential energy that depends on separation distance (just like the gravitational potential energy between a vase and the ground depends on how high up it has been placed).