Remote control units, how operated?

Looking at some pics on railpics.net i came across from RC units that had hte windows covered up. It got me thinking, how are these operated and where from? Whats the point?

to me it seems kinda pointless to have RC units. You still need someone to operate somekind of control setup and probably to couple/uncouple the cars. Why would it beneficial to do it this way then to have someone inside the cab?

I take it you are speaking of radio control engines used in yard switching operations. These came into general use after I retired, but the way I understand it the switch foreman has a radio belt pack with which he or she controls all engine movements. One other person works with the foreman on the ground. The engineer position is therefore eliminated with a corresponding reduction in labor costs for the carrier. RC units are simply all about saving money so far as the carrier is concerned.