Attributes and properties of objects

An XMS object can have attributes and properties, which are characteristics of the object, that are implemented in different ways.

Attributes
An object characteristic that is always present and occupies storage, even if the attribute does not have a value. In this respect, an attribute is similar to a field in a fixed-length data structure. A distinguishing feature of attributes is that each attribute has its own methods for setting and getting its value.
Properties
A property of an object is present and occupies storage only after its value is set. A property cannot be deleted or its storage recovered after its value is set. You can change its value. XMS provides a set of generic methods for setting and getting property values.