The first Agile methodology we're going to talk about is Scrum. Now this is probably the most widely practiced methodology and in this module, you're going to learn how to use Scrum, the roles, the practices. That it's delineated so that you can figure out if and how you want to apply it to your practice of Agile. Scrum actually has a history that predates its use in software but it was really worked into its modern form by Ken Schwayberg, Kevin Sutherland and a few other folks and formalized in a book called Agile Development with Scrum that was first released in 2001. There are three roles in Scrum. The first one is the Scrum Master. And the Scrum Master's job is to take whatever practices and parameters you're adopting from Scrum, and make sure that those are consistently applied so that the team can use them. So they're less like a cop, a enforcer of Scrum, even though kind of it sounds like that, and more like a coach. So, I think partly because of the kind of connotation of this title, who would you rather go camping with? A Scrum Master or an Agile coach? You'll often hear the kind of work that the Scrum Master does sometimes referred to as, Agile coaching. Just helping people understand and apply the practice of Scrum and that's their main job. And, you'll probably find that you need the Scrum master to do quite a lot of work when you have a new team, if you're initially adopting the practice of Agile. And if things are going well, you'll probably find them having to do less and less in that role as the team moves towards this pinnacle or practice of self-organization. So naturally, using the rules of Scrum to self-organize and do what makes sense. The next role is the product owner. And the product owner role, their job is to prioritize the backlogs, write user stories, and be the voice of the customer. Now that's their job. The reality is it's very important that it's not just one person that's solely responsible for creating narrative. It's strong narrative collaboration across the whole team that will help you drive to good well thought out product. So this person is the lead responsible person in this role but it's the hallmark of a high functioning team that everyone is heavily involved in doing this. And the other thing I would say is that it's not the Product Owner's job in a well run team, I would say, to shield the developers from customers or users. I think it's important to, we talked about, bringing your whole team on a design sprint. So everybody can get out there and see what's really relevant, what's really valuable, to what they're doing. So, again, product owner is the advocate, the lead, the sort of ultimate responsible party on this area, but they shouldn't be the only person doing it. And then finally, you have the development team. An Agile team in general is usually five to ten people, with seven being kind of the sweet spot. And the development team is everybody else, developers, designers, testers, documentation and media, if that applies. So this is really the rest of the team. So these are the roles in Scrum. And, yes, multiple people can fill these roles, especially if you're working in a small team. But the mechanics of Scrum suggests that you think through who's going to do this and that they consistently are the lead person on helping the right things happen in these areas.