Collections and Worlds are both currently in beta as we build out the features for all creators on Foundation.
Collections are created by individual artists. A collection can consist of many artworks, focused around a core idea. Every artist that has a collection on Foundation has deployed their own custom smart contract to directly mint NFTs from. Collections can be thought of as albums.
Worlds are community-curated spaces to explore on Foundation that include lists of featured artists and artworks. Worlds can be thought of as playlists.