LDAP compare is a nice little module that actually reads all computer objects from your Active Directory in to a table. It tries to find matching entries in the servers and workstation tables in the IT Assets database.
If you go to the column Type and but a space as filter, you actually might see systems that are in Active Directory but not in your database.
Further can you e.g. filter in Deployment Status for retried systems, those computer objects should theoretically not exist in your Active Directory anymore.
It helps you auditing your Active Directory against the known and documented assets and lowers therefor as well a potential security risk within your network.
LDAP compare depends on two or more entries in the Sys Config table. This is because the LDAPCompare\Domains parameter can define one or more domains and depending on this, you might have more then just two entries.