Bahmni EMR is a user interface layer that is built on top of OpenMRS. Where possible, Bahmni depends on configuration that can be performed directly in OpenMRS.
For example, OpenMRS provides a mechanism to define custom attributes for a patient. Bahmni uses this underlying facility to show custom attributes for the patient on the Registration app. However, on Bahmni, there is also a way to define mandatory attributes for a patient. This cannot directly be achieved by configurations in OpenMRS. Such extended customizations are achieved in Bahmni using configuration files.
Any feature that is to be configured in Bahmni will typically need a combination of OpenMRS configuration and modifying the Bahmni configuration files.