Field mapping is the mechanism by which bxp software maps its data fields to the fields in your form. bxp software designates fields using its own nomenclature. e.g. strCDA_41_field_1_3strCDA_41_field_3_1. (Campaign database 41, field 1, subpart 3). In BE this represents the surname in a complex title block. Clearly, it’s easier for us to understand Surname so field mapping allows you to tell BE that strCDA_41_field_3_1 = Surname.