Directory services matter to nearly every organization because they help centrally manage information and thereby reduce the costs of computing services. LDAP (Lightweight Directory Access Protocol) is a set of protocols that have become the internet standard for accessing directories. Many people need to understand directory services and LDAP in order to make decisions for their business. The books currently available are too advanced for technical managers and those new to directory services. This book is designed to fill that need. The author spends the first half of the book exploring how directory services and LDAP work and then the second half discussing the most popular implementations - OpenLDAP, Microsoft Active Directory, and Directory Server - for those who are trying to compare products. This book provides the technical foundation that will enable IT managers to make sound business decisions and developers to move on to more advanced books.