Normalized hierarchical relationship.

This is the default option for source or target definitions imported from a WSDL file. In a normalized hierarchical view, every element or attribute appears once. One-to-many relationships become separate XML views with keys to relate the views.

Entity relationship.

Use this option to create relationships between views instead of one large hierarchy. When you create a web service source or target with an entity relationship, the Designer generates separate views for multiple-occurring elements and complex types. The Designer includes views for all derived complex types.