Groups allow you to share access to Accounts, Cars, and/or People (ACP). Any member of a Group can add an ACP to that Group, then all members of that Group can add/edit/delete entries (transactions/logs/visits) for that ACP. However, only owners (creator) of the ACP can edit/delete the ACP itself, including adding or removing it from a Group.
Finally, only the owner (creator) of a Group can edit or delete the Group.

Name Owner Members Accessible Accounts Accessible Cars Accessible People