Is there a difference between "whiskey" and "scotch"? Is Canadian Whiskey a "scotch" or just whiskey?
It's all whiskey - (any booze distilled from fermented grain mash)
Scotch is made only from malted barley, and by law may only be called Scotch if it was made, and subsequently aged in barrels, in Scotland, for a minimum of three years. There isn't a specific requirement for the barrels themselves, and distillers routinely reuse (especially sherry) ones obtained from other products as a way to enhance flavor.
Bourbon is from the USA, and is made from a majority of Corn (51%, minimum). And by law must be aged in new 'charred, white oak' barrels. Only US whisky made this way may be called Bourbon. Note: since the requirement in the US is only new barrels, most of the used ones are sold to Scotland and reused.
Tennessee whisky is Bourbon which has been filtered through charcoal. Mostly that means Jack Daniels
Canadian whisky comes from....
'Sour Mash' is when the distiller starts a new batch of mash using some of the old mash, instead of new yeast.
Rye is whisky made from Rye.
Irish whiskey is made in Ireland. Their rules are more relaxed. They also tend to triple distill the alcohol, which often results in a cleaner, lighter taste.