okay, i googled it because stuff like that drives me nuts. lol scotch whisky is made in scotland distilled from water and malt, irish whiskey is distilled in ireland. bourbon is american whisky distilled from no less than 51% corn mash, while rye whiskey is distilled from no less than 51% rye mash.
Whisky and whiskey can usually be interchangeable, i think the ey is more a british spelling, kind of like honor/honour, donut/doughnut.