Job Server, Queue & Job Destination Difference

Hi.  I'm a bit unsure of the difference between the settings above.  If I look at a defined Job Server, it will list both the server name, a queue and within the OIM Service tab, there will also be a JobServiceDestination.  I think I grasp that the Server property controls where the Job Server is installed (the physical server), but the Queue and the JobServiceDestination both seem similar?  Further confusion is brought by the fact that multiple destinations can be defined, even though there is only one queue.

It also seems that if I install the first Job Service by default it will install the Service on the actual SQL server;  I'd imagine I'd want the Job Service installed on a separate server.

Thanks for any explanation,