The true value in Lightweight Directory Access Protocol (LDAP) is its use as a standard for applications to interact with AD. The actions of Add, Modify, Move and Delete I mentioned above are exposed in code that a developer can use write into their applications in order to store and retrieve data in AD. This is one of the many things that make Microsoft Active Directory and Lightweight Directory Service (also known as ADAM) such great solutions for writing business solutions. LDAP is simply one of many exposed entry points for data access in AD-otherwise known as Active Directory Service Interfaces. One stop shopping-code samples and references, a wide array services interfaces, reliability and tough integrated security are just how Microsoft AD rolls.
Full Article: AD Blog