Volt

• "Volt" (symbolized as "V") is the unit name derived for the quantity of electric potential. Volts, or voltage, measure potential, as opposed to "joules," which measure amount of energy, or "coulomb," which measure charge.
  
  

Electric Potential

• "Electric potential" (volt) is the amount of potential energy per unit of charge (measured by coulomb). Each volt equals a potential of one joule per coulomb.
  
  

Voltage

• The "volt" measurement is used as the international measure for electric potential throughout the world, but the actual voltage used in commercial and residential sites across the world varies from 100 to 240. Most appliances can handle a difference in voltage as long as the frequency (measured in hertz and kilo-hertz, "Hz" and "KHz," respectively) is similar.