Pi_rules response to your post is correct, I just want to add some pedantic commentary.
People think "whisk(e)y" refers to something specific. Instead whisk(e)y is the most generic term for a family of alcoholic beverages. I usually use a geometry analogy: whisk(e)y==quadrilateral. A quadrilateral is any four sided shape (in two-dimensions).
If we start demanding more definitions on our quadrilateral we use different terms. If one pair of sides are parallel to each other, the shape is a trapezoid (trapezium). And if both pairs of sides are parallel to each other, this is a parallelogram. However, both trapezoids and parallelograms are still quadrilaterals.
Parallelograms can be broken down even further. A parallelogram with four 90-degree/right angles is a rectangle. A parallelogram with four equal sized sides is a rhombus. Likewise, a rhombus with four right angles is a square. Squares are also rectangles by construction. And all these shapes are still quadrilaterals. I might not be 100% correct in my geometric definitions, but the point of my analogy is that there is a family of shapes, starting with a quadrilateral, and additional definitions result in different names.
Whisk(e)y just means any grain that has been fermented, distilled, and then aged in wood barrels. Whisk(e)y can be made from wheat, corn, rye, barley, and malted barely. In fact it could be made of rice, oats, millet, etc. although I don't know if any whisk(e)ys that are made from these grains. (Aside: Sake is made from rice but not distilled and thus not a whisk(e)y). Not surprisingly, rye whisk(e)y is made from rye.
Scotch whisky comes from Scotland. Single malt scotch whisky means that the whisky is made in Scotland and comes from a single distillery where malted barley was used as the grain. Bourbon is an American whiskey which is made from at least 51% corn which is aged in new barrels only (so barrels can't be reused). Bourbon must also be distilled in Kentucky.
As you can see these definitions start to get myriad and confusing. Some of these terms are codified by law. To call a whiskey a bourbon you must follow a certain prescription by law, or else you cannot label it as bourbon.
Perhaps to be explicit and answer multipart/mixed question, the term whisk(e)y is not dependent on the grain the product was made from nor where the product originated. There are American malt whiskeys, made from malted barley and even roasted over peat to give it a the smoky flavor some Scotch whiskies have. There are Scotch whiskies made from wheat and unmalted barley, named single/blended grain whiskies depending on whether the whisky comes from a single distillery or whether it is blended from many sources. Rye whiskey was historically distilled in large quantities in the USA. Today Canada is a major source of rye whisky. Ireland, Japan, Austraila, etc. There are distilleries in many European countries, even in Brazil, Argentina, South Africa, India, etc. etc. All make whisk(e)y.
So in conclusion, please don't assume that the name whisk(e)y denotes what ingredient was used to distill the product or where it was made. Whisk(e)y can come from any grain, and is worldwide in production.