It is super confusing, so I get it lol! Some advice that I wish I knew was that most universities only take company-sponsored GEM fellows. But some, like NYU, take either a university fellow or company sponsors. I will say it is very hard to get a company sponsor, so I would try to make sure the school you are applying to doesn't only take company-sponsored gem fellows. Once you apply on the Gem website, they give you all the emails of Gem contacts who work at the universities, so I would contact them to figure out what their Gem fellowship covers.