1. User-generated events, such as a mouse click, send off a message to the OLE application.

2. The message tells the application (known in OLE parlance as a container) what action it should perform.

3. Containers and OLE controls communicate through a messaging interface. Every OLE control has a built-in receptor, called a sink, to receive instructions from an application.

4. Sometimes a user generates an event within an OLE Control. To communicate this event to the container, the control tells the container to dynamically set up a sink to receive the communication