Product Backlog:

• High level feature descriptions are gathers early but they are minimally described at that time and are progressively refined as the project progresses.
• It is a list of all desired functionality not yet in the product.
• It is maintained by the product owner and kept in priority order which is why it is also called as PRIORITIZED feature list.
• Unlike the traditional REQUIREMENTS a product backlog is highly dynamic, items are added, removed and reprioritized each sprint as it progresses and team learn more about product, the users and so on.
• Changes in business requirements, market CONDITIONS, or technology, cause changes in the Product Backlog, making it a live artifact.
• High ordered items are clearer than low ordered items.
• More precise estimates are made based on the greater clarity and increased detail.

Sprint Backlog:

• Sprint Backlog consists of selected items from the product backlog which has complete DETAILS and clarity of requirements and on top priority.
• Sprint Backlog is a FORECAST by the team that what all functionalities will be made available in the current sprint.
• The team modifies the sprint backlog as the sprint progresses which helps in tracking the sprint. Modifications includes tasking out the user stories.
• Whenever some task is completed it is moved to completed and when all the tasks related to one user story reached completion (Definition of Done) state then after sprint review this user story is moved to completion.
• Sprint Backlog depicts the real time picture which team decided to accomplish in a sprint and it is completely owned by the team.