A replacement for the NetInfo service in NeXTSTEP and early Mac OS X, Open Directory is an LDAPv3 service delivered as Directory Services, and essential to permissions, authentication and more.
Directory Utility
Advanced settings for users have been moved out of Users & Groups, but are still accessible in Directory Utility for those who are careful not to do anything hazardous.
Accessing information about you as a user and a great deal more, using the Advanced Options dialog for user accounts, and Directory Utility.
Changing permissions is straightforward in the Finder or command line. But how would you go about changing a file/folder’s owner or group?
These services don’t often appear in the limelight, but the recent vulnerability in High Sierra reminds us how important they still are.
The Eclectic Light Company 