The processes of making scotch, whiskey, and bourbon are very similar, but it’s only scotch if it’s made in Scotland, just like it’s only bourbon if it’s made in the United States. Whiskey and scotch guidelines allow for the alcohol to be aged in barrels other than the very specific charred white oak barrels used in bourbon production. And, to make things more complicated, whiskey spelled without the “e” is scotch.
Scotch can only be called scotch if it’s made in Scotland. (But they might look at you funny if you go there and ask for it. There, it’s just whisky.)