Potential Difference vs Electromotor Force

P.D is the energy provided to each charge within the circuit. It is also the difference in potential between two points. EMF accounts for the resistance within the battery it provides energy to the resistor in the battery.

where is EMF, is the resistance of the circuit and is the internal resistance of the battery.

The EMF of a cell is equal to the electrical energy per unit charge gained by the charges as they pass through the cell.