A directory service maps the names of network resources to their network addresses
A directory service is shared information infrastructure for locating, managing, administering and organizing resources
Resources can be any object like volume, folders, files, printers, users, groups, devices, telephone numbers
It is a critical component of a network operating system
A directory server (name server) is a server which provides a directory service
Each resource on the network is considered an object by the directory server
Information about the object is stored as a collection of attributes associated with that object
Directory Services
Domain Name Server (DNS) : The directory service for the internet
Microsoft Active Directory
Apache Directory Service
Oracle Internet Directory (OID)
OPenLDAP
Cloud Identity : Google’s Directory Service