The new version is also being released alongside a 'next-gen' update for owners of the Special Edition and Anniversary Edition, which is free and will reportedly 'optimize the game with enhanced graphics, faster loading times and more.' The FAQ suggests this is only available to players on next-gen consoles.
It'll add things like fishing and aquariums and a lot more. The Creation Club is Bethesda's source for officially sanctioned mods, which cost money to buy for the previously released Special Edition. The Anniversary Edition, if you don't know, is a new version of Skyrim that's gussied up with every piece of Creation Club content released thus far.