The COM (Component Object Model) interface defines the externally visible binary structure of a COM object. The COM object is hereby the implementation of this model and can be based on several interfaces which define access to the object. It offers runtime access to the incorporated interfaces of a COM object and interprocess communication. Reference counting is implemented to manage the object's life cycle. Interactions between components are based on method-accesses defined in interfaces. COM applications are restricted to run locally on single computers only.