From OpenSCADAWiki
Directory service or name service maps the names of network resources to their respective network addresses. It is a shared information infrastructure for locating, managing, administering and organizing everyday items and network resources, which can include volumes, folders, files, printers, users, groups, devices, telephone numbers and other objects. A common use of LDAP is to provide a central place to store usernames and passwords. This allows many different applications and services to connect to the LDAP server to validate users. The protocol provides an interface with directories that follow the 1993 edition of the X.500 model:
- An entry consists of a set of attributes.
- An attribute has a name (an attribute type or attribute description) and one or more values. The attributes are defined in a schema.
- Each entry has a unique identifier: its Distinguished Name (DN). This consists of its Relative Distinguished Name (RDN), constructed from some attribute(s), in pairs {name}={value} separated with the sign '+', in the entry, followed by the parent entry's DN, separated with the sign ','. Think of the DN as the full file path and the RDN as its relative filename in its parent folder.