title: COM Dual Interfaces
body: <p>A dual interface in COM is one that is able to be accessed via a DispInterface or via VTable methods.</p>
  
  <p>Now can someone tell me what is exactly what the difference is between the two methods?</p>
  
  <p>I thought that a VTable is a virtual table which holds the pointers to the different functions when implementing a class hierarchy which has virtual functions that can be overridden in child classes.  However I do not see how this is related to a dual interface in COM?</p>