In short: CAM for Cameras and LBUS for LBUS devices (motors, LCubes, OCU-1s, Master Grips etc).
The RIA-1 is a little different to previous devices with LBUS ports, where you may have used an LBUS cable to connect that device with a camera. If you are using the RIA-1 as a motor controller on a camera it is vitally important that you use the CAM port on the RIA-1 to interface with your camera, and the LBUS ports on the RIA-1 to connect to motors.
When used as a motor controller, the RIA-1...