A flat model is a data structure in which there are no branches in the hierarchy after BaseDN and in which user entries are registered in the hierarchy located just after BaseDN.
If the flat model is used, the entries in the hierarchy after BaseDN are searched for an entry that has the DN that consists of a combination of the login ID and BaseDN. If such a value is found, the user is authenticated. The following figure shows an example of the flat model.
Figure. Example of the flat model
