A product backlog is an ordered list of work a team may do to improve a product. It is like a shared list of ideas and tasks, arranged so people can discuss what matters most next.
The list might include fixing a confusing screen, adding a requested feature, or improving how quickly a page loads. The team can adjust the order as it learns more.
Being on the backlog does not mean a task is promised or already underway. It is a place to keep and prioritize possible work.