Attribute mapping maps the user attributes from the LDAP Server/Active Directory with Joomla user attributes.
For example, if the username attribute of the LDAP Server/Active Directory is samaccountname and the username attribute of Joomla is username, then samaccountname is mapped to username.
To perform attribute mapping, enter the username and click on the "Check Attributes Receiving' button. After clicking on this, a window will appear which lists all the attributes coming from the LDAP Server/Active Directory.
You can check the attributes coming from your LDAP Server/Active Directory and map them accordingly with Joomla’s attributes.