Property definitions
A property is a named value that is associated with a business object, such as the partnumber of a product object. You can use a property definition to describe a specific property to the framework.
You do not need a property definition for every property. You must declare a property definition only when you must describe the property to the framework. For example, if the property is a required property, you can use a property definition to indicate that it is required. If the business user does not specify a value for a required property, the framework displays a warning.
The PropertyDefinition definition describes a single object property of the
parent object definition. A property definition can be declared only as an immediate child
definition of an instance of the ObjectDefinition definition.