The main benefit of using LDAP is the consolidation of certain types of
information within your organization. For example, all of the different
lists of users within your organization can be merged into one LDAP
directory. This directory can be queried by any LDAP-enabled
applications that need this information. The directory can also be used
by users who need directory information.
Other LDAP benefits include its ease of implementation (compared to
X.500), and its well-defined Application Programming Interface (API),
which means that the number of LDAP-enabled applications and LDAP
gateways should increase in the future.
On the negative side, if you want to use LDAP, you'll need LDAP-enabled
applications or you'll need to use LDAP gateways. As mentioned
previously, LDAP will only increase in usage, but at present, there
aren't a plethora of LDAP-enabled applications available for
Linux. Also, while LDAP does support some access control, it does not
support as many security features as X.500.