Do licenses apply to one book or all books?

Each license applies only to the specific book you bought it for, not to your whole account.

That means if you buy the Educational, Commercial, or Author license on one book, those rights cover that one book. A second book in Your Library still starts on the default Personal license until you buy a higher-tier license for it too. There's no account-wide or multi-book license.

The license itself has no renewal — once you buy it, the rights for that book are yours for good. It's a one-time payment per book, not a subscription.

If you want the same rights on several books, buy the matching license for each one. You can do that during creation (in the Review step) or after the fact from the book's menu — see How to buy a different license for an existing book.