The Red-belly snake (Storeria occipitomaculata) is a relatively small snake that rarely exceeds 12 inches in length. It is native to North America, Mexico and Central America, and it is NOT venomous.
The electromagnetic frequency of a wave is defined as how many times the peak of this oscillation moves past a point each second. This has a major effect on the properties of the wave, including its energy.
Your definition is better. EMF is the energy supplied to electric charge. It is measured in Joules per Coulomb and 1 Volt means 1Joule per Coulomb. POTENTIAL DIFFERENCE is energy dissipated (given up) by charge passing through resistance. This also measured in Joules per Coulomb or Volts.