We call the potential energy that a positively charged unit situated at a certain point would have, the potential of a charge at that point. Its unit is the volt. The potential is positive if the charge is positive and negative in the opposite case. Its value is determined by:
                                              
where r is the distance between the charge and the point considered.

The potential created by several charged particles is the sum of the potentials created by each one.

The work carried out by the field when a charge q moves from one point to another  (1 and 2) in a field is determined by the potential at these two points.:
                                               
                                                  W= q·(V1-V2)