What is possession and reading?
Possession says whether the book is on your shelf. Reading says whether you have read it. They are independent, so an owned book can be unread and a wanted book can already be finished.
Four combinations do most of the work. Owned and unread is the pile waiting for you. Owned and reading is the book on the table. Owned and completed is the set you have finished and kept. Want and unread is the list for the next shop trip.
Reading trackers ask “where are you in the series?” and assume one answer. A shelf of mixed editions needs a different question for each book. You can be halfway through the VIZBIG set and still be missing a single you meant to replace. Each entry has its own reading state.
Filters in the app are built on the pair: show me everything owned, show me the unread owned books, show me what I want. Stats use the same split, so the completed bar is not secretly a count of books you merely bought.
Related
See the words on a real set in the edition catalog.