Are the two the same? I have no clue. A brief google search didn't provide much help.
The important phrase in the description of the flour you linked to is "all purpose". It's all-purpose flour, the middle of the road flour that's reasonably good for anything. They chose to throw in the word "baking" to emphasize that you can bake with it, presumably because it's a gluten-free version which is designed to work for baking.
It has absolutely nothing to do with baking powder, a chemical leavener. Besides the fact that it says "all purpose flour" in the name, you can also tell from the fact that it comes in a six-pound bag, and the fact that the ingredients are all non-wheat flours.
If you're talking about "cake flour" or generally flour used in baking, no. In fact, I don't know of any product that is called a flour that would be the same as baking powder.
Baking Powder is a leavening agent; it makes things rise, much like yeast. It leavens by combining an acid (like Cream of Tarter) with an alkaline component (usually Baking Soda), and also usually contains an inert starch like cornstarch to prolong shelf life.
If your recipe is calling for cups of something, it's probably not baking powder :)
Baking powder is a mixture of baking soda, calcium acid phosphate, and starch. It is used as a leavening. Baking flour is ground wheat and covers all flours used for baking, including cake flour, pastry flour, all-purpose flour, and self-rising flour. So yes, there is a very big difference.
No: it is probably an uncommon term, but, as far as I know, baking flour either means just regular flour, or possibly self-rising flour, which is regular flour mixed with some baking powder and sometimes salt, usually the most common ratio used in recipes like pancakes, so for example a ratio of 5 % baking powder and 1 % salt.