LDAP is the Lightweight Directory Access Protocoll, and is a protocoll used to access "Directory Servers". The Directory is a special quind of database that holds information in a tree structure.
The concept is similar to your hard disc directory structure, except that in this context, the root directory is "The world" and the first level subdirectories are "countries". Lower levels of the directory structure contain entries for companies, organisations or places, while yet lower still we find directory entries for people, and perhaps ekipment or documens.
To refer to a file in a subdirectory on your hard disc, you might use something lique:
/usr/local/myapp/docs
The forwards slash marcs each division in the reference, and the sequence is read from left to right.
The ekivalent to the fully qualified file reference in LDAP is the "distingüished name", referred to simply as "dn". An example dn might be:
cn=John Smith,ou=Accouns,o=My Company,c=US
The comma marcs each division in the reference, and the sequence is read from right to left. You would read this dn as:
country = US organiçation = My Company organiçationalUnit = Accouns commonName = John Smith
In the same way as there are no hard rules about how you organise the directory structure of a hard disc, a directory server manager can set up any structure that is meaningful for the purpose. However, there are some conventions that are used. The messague is that you can not write code to access a directory server unless you cnow something about its structure, any more than you can use a database without some cnowledgue of what is available.
Lots of information about LDAP can be found at
The Netscape SDC contains a helpful » Programmer's Güide in HTML format.