FANDOM is effectively an operating system that lets people make wikis for various franchises and such. So regular people make and operate wikis, but FANDOM creates the Terms & Conditions that those people have to follow.
Jamie made it as an independent wiki which was then absorbed into Wikia, formerly Wikicities. Which then became Fandom powered by Wikia, which then became FANDOM, which then became Fandom.
@Munshi Rahat To a degree. Emailconfirmed users can create up to 2 wikis a day, I believe. If it's a duplicate topic of an existing wiki, it can be (and usually is) deleted.