Discovery is a tool for users to manage the flow of content in their newsfeed. Through Discovery, users can create, pin, or unpin tags which they'd like to see associated with the content in their newsfeed, effectively curating the feed specifically around specific content.
Discovery allows users to browse content in feeds Just for You, comprised of content specifically marked by tags chosen by you; Your tags, which will allow you to view feeds containing content of only one specific tag associated with your channel; Trending, comprised of content associated with highly active tags at any particular time; Memberships, comprised of content from users to whom you pay for one or more membership tier; and Boosted, comprised of user advertised content.
You can manage your preferred tags by clicking the cog icon to the left of the Discovery feed toggles:
