Ugh, I spent entirely too much time arguing this when I was still in school, ironically the most time we spent arguing with men that were more than twice my age and felt way too strongly about this.
This is the right answer and I will not be taking any questions: 🙃
If it comes as a set with matching bottoms(or a gold chain) = Tracksuit/Sweatsuit
Light single layer + hood = hoodie
Light (single layer) + zipper/buttons + no hood = Jacket
Light (single layer) + knitted = sweater or sweater jacket if it opens
The other lighter layers with no hardware are just pullover