Server-activated types can be either single call or singleton. If a class is registered as a single call type, a new instance is created each time a call from the client arrives. All calls to a singleton object are handled by one instance of that object, unless that object has been collected.
Any client that knows the URI of a registered server-activated object can obtain a proxy for this object by registering the channel it prefers with ChannelServices and activating the object by calling new or Activator..::.GetObject. To activate a server-activated object with new, you must first register the server-activated object type on the client using the RegisterWellKnownClientType method. By calling RegisterWellKnownClientType, you are giving the remoting infrastructure the location of the remote object, which allows the new keyword to create it. If, on the other hand, you use the Activator..::.GetObject method to activate a server-activated object, you must supply it with the object's URL as an argument, so no prior registration on the client is necessary.
For a detailed description of server-activated objects and remote object activation, see Activation of Remote Objects.