NetInfo is the system configuration database in NeXTSTEP and Mac OS X versions up through Mac OS X v10.4 "Tiger". NetInfo replaces most of the Unix system configuration files, though they are still present for running the machine in single user mode; most Unix APIs wrap around NetInfo instead.
NetInfo stores system wide network-type configuration information, such as users and groups, NFS mounts and printers in a network accessible database.
NetInfo was a precursor to LDAP.