It's not that easy on the Internet - yet. Inside companies, managing user information is a much more pressing and serious problem. Currently, many organizations have to manage multiple directories that are incompatible with one another, making the management and maintenance of user information an expensive and time-consuming problem. For example, when an employee joins a company, information and access rights often have to be entered manually in multiple directories. This situation is repeated every time the employee changes departments or locations, or leaves the company.
Some directories are cross-platform, but work only in a single application environment.
Other directories provide a limited set of directory services across applications, but only on a single platform. The Lightweight Directory Access Protocol, or LDAP, provides the solution. LDAP is based on the X.500 directory protocol, but is simpler, easily extensible, and can be embedded into a variety of clients, servers, or applications. LDAP is also a terrifically fast and scalable protocol, with current implementations supporting hundreds of thousands of entries per server and a query response time of a few milliseconds. Because it runs across applications and operating systems, it fits into multiple environments.