User Group
To help you manage user accounts more efficiently, TeamCity provides User Groups. A user group allows you to:
Assign Role and Permission to all users included in the group at once: users get all the roles of the groups they belong to.
Set the Subscribing to Notifications for all users in the group: all the notification rules defined for the group are treated as default notification rules for the users included in this group.
You can create as many user groups as you need, and each user group can include any number of user accounts and even other user groups. Each user account (or the whole user group) can be included into several user groups as well.
"All Users" Group
All Users is a special user group that is always present in the system. The group contains all registered users and no user can be removed from the group. You can modify roles and notification rules of the "All Users" group to make them default for all the users in the system.
Guest User does not belong to the All Users group.
The "default user" roles cannot be edited. Please use defaults in "All User" group.