Personal context vs Org context

Solo authors run Books in Personal context — turn it on in Account → Personal modules. Books you create are owned by your user. Small presses or agencies run it in Org context — every book is owned by the org, and editor/admin roles control who can publish. Some features (Email Campaigns launches, Serial subscription plans, Author-site blocks) require an org; you'll see clear messages and can move the book to an org any time.