What is LDAP? What is LDAP?

LDAP is the abbreviation for the English Lightweight Directory Access Kyoto, the Lightweight directory accesses protocol. It is a protocol to access the online directory service. What is a directory? The LDAP directory can store various types of data: e-mail addresses, message routing information, human resources data, public keys, contact lists, and so on. The latest version of the LDAP protocol is defined by RFC 4511.

It's based on the X.500 standard, but it's much simpler and can be tailored to your needs. Unlike X.500, LDAP supports TCP/IP, which is necessary for accessing the Internet. The core specifications for LDAP are defined in the RFC, and all LDAP-related RFCs can be found in the Ldapman RFC Web page.

The most basic form of LDAP is a standard way to connect to a database. The database is optimized for read queries. So it can get the results of the query quickly, but in other ways, such as updates, it's much slower. It is particularly noteworthy that LDAP is typically used as a hierarchal database rather than as a relational database. Therefore, its structure is better represented by a tree than by a table. Because of this, you cannot use SQL statements.

In short, LDAP is a quick way to get centralized, static data about people or resources.

LDAP is a special kind of database. But it is important to understand that LDAP is different from the general database. LDAP optimizes queries and has a much better read performance than write performance.