title: The relationship between OPC and DCOM
body: <p>I am trying to grasp the link between OPC and DCOM.  I have watched all four of the tutorials <a href="http://www.opcti.com/what-is-OPC-case-study.aspx" rel="nofollow noreferrer">here</a> and I think I have a good feeling for what OPC is, but in one of the tutorials (the third one 35 seconds in) the narrator states that OPC is based on DCOM, but I do not understand how the two are really linked.  My confusion comes from a question my professor posed in which he asked "How and where would you deploy OPC instead of DCOM and vice-versa."  His question makes it seem like the two are not as linked as my research suggests.  I'm not looking for anyone to answer the question my professor asked, I just want to know the relation between OPC and DCOM, then I can figure the rest out.  Specifically I would like to know if: 1.) One is always based on the other 2.) One can always be deployed without the other.</p>