Agile Product Definition
In Scrum the Product Owner is responsible for defining the features and releases of the product. The Agile Triangle refers to this overall practice of defining the product and releases as Product Definition.
Agile Product Management has a long history with many different techniques and processes. Each organization or team needs to define its own Product Definition process, outlining their existing competencies and determining the competencies they desire.
Product Definition practices can vary widely, but some commonly used concepts are:
Personas to understand how a certain type of user would work with the system.
User journeys to define the overall map of how a user interacts with the system.
Mockups or wireframes to visualize the software interface.
Functional prototypes for exposure to user communities.
User testing to verify product value.
Product Roadmap to define direction, contents and releases for the product
Agile Product Definition is an ongoing process and the roadmap is a living tool as long as the product is alive. The product is never considered defined in totality, rather it is continuously refined and re-defined based on what is highest priority for the business.
There is nothing in Scrum that defines how the Product Owner should create and manage the Product Backlog. The Scrum Guide only says the Product Backlog needs to be a prioritized list with the top items estimated and understood enough to develop.
Scrum does not define the work that Product Owner's need to do to get their stories ready for development. This topic is covered by a world of Product Management practices and every organization needs to define the process that best serves their needs.