Following is the abstract from Joule’s page on Wikipedia:
I have come across clients / dealers, who says Joules is not the same as Ws and Ws is more powerful. The fact is 1 Joule is exactly same as 1 Ws. So a 1200J Flash light will give the same power as the 1200ws flash light. The measure Joule is more popular in Europe where as the measure Ws is more popular is USA. For more technical and scientific explanation please read //en.wikipedia.org/wiki/Joule
The joule (/ˈdʒuːl/ or sometimes /ˈdʒaʊl/), symbol J, is a derived unit of energy, work, or amount of heat in the International System of Units. It is equal to the energy expended (or work done) in applying a force of one newton through a distance of one metre (1 newton metre or N·m), or in passing an electric current of one ampere through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889).
One joule can also be defined as:
- The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one ‘”coulomb volt” (C·V). This relationship can be used to define the volt.
- The work required to produce one watt of power for one second, or one “watt second” (W·s) (compare kilowatt hour). This relationship can be used to define the watt.
If you have any doubts or need more information, please feel free to email me