It should be noted that SOAP does not address object activation, marshaling objects/references, garbage collection, etc.  Further, as SOAP is a wire protocol, it does not provide an activation mechanism.  However, we can still use these in our applications as a layer on top of SOAP if required.  This article has provided a detailed discussion on SOAP, why SOAP is required, the advantages and disadvantages of SOAP and the support for SOAP in Web Services and Microsoft .NET Remoting technologies.