In the wizard, you define the objects and fields contained in the object structure, along with properties for those fields. The information you specify is written to object.xml in the master index project. This file defines the objects stored in the master index application and their relationships to one another. It also defines the fields contained in each object, as well as certain properties of each field, such as length, data type, whether it is required, whether it is a unique key, and so on. This file contains one parent object; all other objects must be child objects to that parent object. The object structure you define in object.xml determines the structure of the database tables that store object data, the structure of the Java API, and the structure of the OTD generated for the project.