The list of requested features and functions that remain for the project team to deliver to the customer.

In agile software development, features and functions are bundled up into an MVP and subsequent releases.  The product backlog is the list of customer requests that have not yet been delivered.

The backlog requires prioritization, which is often performed by the product owner or product manager role in organizations that are using agile to deliver the product to their customers.

As a business analyst, you may be expected to act as the product owner or the facilitator of the product owner in your organization. Knowing how to manage the backlog is a skill that becomes useful for the business analyst in such circumstances.