Scrum Product Backlogs
In this chapter I describe the important role that the product backlog plays on a Scrum development project. I begin by describing the different types of items that typically populate a product backlog. Next I discuss four characteristics of a good product backlog and how good backlog grooming helps ensure that those characteristics are achieved. I then describe why the product backlog is a key element in managing fast, flexible flow at both the release and sprint level. I end by discussing how we determine which and how many product backlogs we should have.
Overview
The product backlog is a prioritized list of desired product functionality. It provides a centralized and shared understanding of what to build and the order in which to build it. It is a highly visible artifact at the heart of the Scrum framework that is accessible to all project participants (see Figure 6.1).

Figure 6.1. The product backlog is at the heart of the Scrum framework.
As long as there is a product or system being built, enhanced, or supported, there is a product backlog.