Every member in Teams has a role, and each one has different permissions.
- Owners
- Team owners manage certain settings for the team. They add and remove members, add guests, change team settings, and handle administrative tasks. There can be multiple owners in a team.
- Members
- Members are the people in the team. They talk with other team members in conversations. They can view and usually upload and change files. They also do the usual sorts of collaboration that the team owners have permitted.
- Guests
- Guests are people from outside of your organization that a team owner invites, such as partners or consultants to join the team. Guests have fewer capabilities than team members or team owners, but there's still a lot they can do.
For a more detailed breakdown of the capabilities for each role please visit: Microsoft's help page