According to The University of North Carolina at Chapel Hill, a volt is represented by joule per coulomb. A volt is the basic unit of electric potential, which is the amount of potential energy per unit charge.
Encyclopedia Brittanica describes a joule as the unit of work or energy and describes a coulomb as an unit of electric charge. The BBC describes these two units in reference to a circuit. A coulomb of charge passes through two points in the circuit. Work has to be done for the charge to pass through. This amount of work over the charge is described as the potential difference, or voltage.