Per AB site;
Effective Wattseconds: This terminology was originally used in 1985 by Inverse Square Systems in conjunction with their "Stroblox" series of high-efficiency self-contained flash units. The term was created because most manufacturers of flash equipment (as well as the press) insisted on the incorrect use of the term "wattsecond" as a definition of light output (in such wrong statements as "This system puts out 800ws of light"). Since the Stroblox system produced on the order of twice the amount of light per wattsecond as did the average "box-and-cable" system at the time, Inverse Square Systems chose to employ the rating "2400 effective wattseconds" as a means of saying "our system puts out an amount of light equal to the average 2400ws system,” even though the actual stored energy of the Stroblox 2400 was only 1200 joules or wattseconds. Indeed, this terminology gave the user a more clear idea of what to expect from the unit than he would have gotten had they simply stated that it was a 1200ws system. We publish wattseconds, effective wattseconds, and Lumenseconds for our flash units, with Lumenseconds being the most valuable method of power comparison.
Lumensecond: A Lumen is a unit of measurement of light intensity emitted by a light source. A Lumensecond refers to a light of 1 Lumen intensity for a duration of one second, or the equivalent, such as 2 Lumens for half a second. The absolute amount of light emitted each time a flash system is fired is correctly specified in lumenseconds. The number of lumenseconds produced by a particular flash system depends on the efficacy, how effectively the system turns electrical energy into light energy, or wattseconds into lumenseconds. The efficacies of commercial photoflash systems typically fall within the range of from 15 to 50 lumenseconds per wattsecond. What this implies is quite simple: a highly efficient 300ws system may produce as much actual light energy as an inefficient system rated at 1000ws.
Wattseconds (Joules): A wattsecond is a measure of electrical energy used in flash systems to indicate the amount of energy in the flash capacitors. Since this is only a measure of electrical energy, and does not take into account considerations such as flashtube efficacy, or flash capacitor/flashtube energy transfer efficiency, it is not necessarily a good number to comparatively assess light output. See also effective wattseconds and Lumenseconds.
Sounds like what everyone else is saying,it just another way to mess people up, I agree with the other postings. have a STANDARD term across the board. Thanks everyone who responded, atleast now I know what the heck im looking at......