Scrum only has a small set of artifacts: the product backlog, sprint backlog, and the product increment. We will briefly review these artifacts here and dive much deeper into them in subsequent chapters.
The product backlog is the product owner's 'wish list'. Anything and everything that they (and other stakeholders) think they might want in the product goes in this list. It could be infinite as there are always new ideas about how to extend a product's features. The product owner maintains the product backlog, although other stakeholders (including the team) should have visibility of and the ability to suggest new items for the list.
The product owner prioritizes the product backlog, listing the most important or most valuable items first. That is, there aren't 10 critical items at the top of the backlog with equal value; rather, there are 10 critical items that are ranked according to their priority or urgency, and they appear at the top of the product backlog, one after another. This is because items at the top are next in the queue to be implemented. Once a team selects items for a sprint (or iteration), those items and their priorities are locked; however, priorities and details for any not-started work may change at any time. Through this mechanism, teams are able to focus on this sprint's work while the product owner retains maximum flexibility in ordering the next sprint's work.
Product owners have many ways of evaluating and thus prioritizing their lists. They may also attribute product backlog items with additional information such as improves brand recognition, allows scaling, infrastructure, contracts greater than 10,000 dollars, and so forth. Attributes are unique to a particular company and a particular product and help the product owner to keep the list in the proper order.
Owned by the team, the sprint backlog reflects the product backlog items that the team committed to in sprint planning, as well as the subsequent tasks and reminders. Team members update it every day to reflect how many hours remain on his or her tasks; team members may also remove tasks, add tasks, or change tasks as the sprint is underway.
The product increment is a set of features, user stories, or other deliverables completed by the team in the sprint. The product increment should be potentially shippable—that is, of high enough quality to give to users. The product owner is responsible for accepting the product increment during each sprint, according to the agreed-upon Definition of Done and acceptance criteria for each sprint deliverable. Without a product increment, the product owner and other stakeholders have no way to inspect and adapt the product.