A product backlog is a list of items to be finished. Items are positioned with highlight descriptions. In an perfect situation, items should be separated into user stories.
Each product should have one product backlog which can have a set of large to very large highlights.
Multiple teams can work on a single product backlog.
Ranking of features is done dependent on business esteem, technical value, risk management or strategic fitness.
Highest ranking items are decomposed into smaller stories during release planning so that they can be finished in future iterations.