[This is preliminary documentation and subject to change.]
The Web-Based Enterprise Management (WBEM) system classes are a collection of predefined classes that are included with the WBEM SDK and are used to support the activities of the CIM Object Manager (CIMOM). They are automatically defined in every namespace. For example, there are system classes to describe providers, events, event providers, and event consumers.
System classes are identified by a leading double underscore in their name. All system classes derive from the abstract base class __SystemClass. Because the system classes are predefined by WBEM, developers cannot create their own system classes by starting a class name with a double underscore. However, they can create classes that derive from system classes.
For detailled information about each of the WBEM system classes, see the System Classes reference.