Add members to a team to help manage your catalog and campaigns. It's important to point out that there is a difference between contacts and team members. That distinction being...that team members will have access to your internal dashboard while contacts will not.
If you create a team, you are automatically assigned the Owner role for that team. There can only be one owner. Ownership cannot be transferred either. When adding other users to your team you can assign specific permissions
Editor (Can Edit)
Provides broad Read / Write / Delete permissions across all assets. Editors, however, do not have the ability to delete the team or modify license settings.
Viewer (Can View)
Provides Read access across all assets. Viewers are unable to modify or delete anything in your dashboard.