What is a Group?
A Group is a set of people involved in a particular activity - think a team, a project or a sub-committee. Each group has its own set of discussions and documents, enabling clear structure of the information that is being shared and collaborated on.
Group Access & Visibility
Groups are only accessible by members and guests that have been added to them.
Standard Members and Admins of a Space will see two sections - My groups and Other groups. As suggested, My groups refers to those groups that a Member or Admin is part of and will therefore be able to access and receive notifications for.
Guests will only see My groups and will not have awareness of those groups that they have not been added to.
Note that Admins are able to add themselves to any group.