Yes, it's the same. RAM: is the device name. "Ram Disk" is the volume name. Similarly, for your floppy drive, DF0: is the device name, "Workbench1.3" is the volume name of your disk.
RAD: is a recoverable Ram Disk that survives reboots. Hence, you can copy your Workbench disk to it and (warm) boot from it. I don't know how to configure it under 1.3, but I'm sure someone here can help with that.