(this article is part of the upcoming “97 Things every Scrum practitioner should know” by Gunther Verheyen (editor))
When applying Scrum to a product with more than one Development Team, there is really little guidance in the Scrum Guide. The Scrum Guide seems focused on one-team Scrum for the most part. The only hint you get is in the Product Backlog section:
Multiple Scrum Teams often work together on the same product. One Product Backlog is used to describe the upcoming work on the product. A Product Backlog attribute that groups items may then be employed. (Scrum Guide November 2017)
We learn that, with multiple teams, we are advised to still use a single Product Backlog. Nothing is mentioned regarding the roles of Product Owner, Development Team, or Scrum Master other than “multiple Scrum Teams” working on the same product.
But how do you decide over priorities? If we take the Scrum Guide literally, there could be more than one Product Owner in each of the Scrum Teams on that product, or it could be the same person for all the teams involved.
Generally, this is the distinction between “Multiple Scrum Teams” and “Multi-Team Scrum”.