I've spent plenty of time looking to learn the difference between salts, Iodine, kosher etc, ..which are easy to understand once explained, however cooking salt seems to slip under the radar except as large bags of salt over & above the typical table salt sized bags we'd all buy for everyday use.
If therefore it is merely a larger sack of table salt (fine pouring grounds) then why is it marketed as a separate & confusing entity?
A couple of good links for those equally adrift as myself ...
http://www.seriouseats.com/2013/03/ask-the-food-lab-do-i-need-to-use-kosher-salt.html
http://lifehacker.com/5991400/why-most-recipes-ask-for-kosher-salt-and-when-its-really-necessary
SO is "cooking salt" merely a uk thing & just another bag of salt cheaper due to it's increased volume?