In 1.0, users can only connect to other users. Books exist as global references, and “who owns what” is visible to each user. Only borrow and lend functions are available.
In 2.0 users can have person-person connections and can join groups. Groups are always invite only, and must be created by a user. Under each book, the user has access to group discussions. If a user is in multiple groups, they’ll see options to switch between group threads. (If a user leaves a group they created, they must elect a new admin.)