This table explains the privileges that are associated with each permission level.
Group calendars are commonly needed among organizations that rely on Microsoft Outlook for managing calendars.
To save resources, the shared document library is not provisioned until the first time that a member attempts to use the “Files” functionality for the group.
All of the resources available to a group are accessed via the single group identity.
When a new group is created, a provisioning process kicks in to create a shared Exchange Online mailbox, which is used to store contributions to group conversations as well as a shared calendar.