Channel Numbers do not seem to match

This is my first experience with any type of DVR, but, unless I have my cables mixed up, the “port” numbers on the back of the DVR do not seem to correspond to the “Channel” numbers.

Is this typcial or is my device mis-labled somehow?

On NVR systems, the ports on the back of the NVR do not correlate with the camera channels. Channel 1 is the 1st camera detected by the system.