I’ve mentioned before the difference between chile and chili, but didn’t have a good reference for the claim.
In case you missed it the last time: The hot peppers used in spicy dishes are chile peppers; the meaty (well, usually meaty, though you can do a vegetarian version) prepared food you eat with nachos is chili. Also, when you dry and grind a single pepper, that is chile powder. When you dry and grind one or more peppers, plus add garlic, cumin, salt and other seasonings to use in making chili, that is chili powder.
Anyway, now I have a reference. No, it’s not authoritative but it’s better than just “because I said so.” Although if you’re good with “because I said so” then that’s fine with me.
They have an extensive selection of chile powders.
If you don’t want to click through to the large picture and read all those upside-down labels yourself, that includes: Ancho, Guajilla, Chipotle, Cayenne, Jalapeño, d’Arbol, Pasilla Negro, Aji Panca, New Mexico, Aji Amarillo, Amazon, Birdseye and Serrano.
And all the way up in the top-right corner …
… is the chili powder.
So, like I said … a single pepper is chile powder, a blend of peppers and other spices is chili powder.
Want more like this? For more recipes like this, that you can hold right in your hands, and write on, take notes, tear pages out if you want (Gosh, you're tough on books, aren't you?) you might be interested in How To Cook Like Your Grandmother, 2nd edition, Illustrated. Or to learn your way around the kitchen, check out Starting From Scratch: The Owner's Manual for Your Kitchen.