Here's a rundown of the weight ratings:
GAWR -- gross axle weight rating, the maximum weight that the axle and its suspension is designed to support. There would be a separate GAWR for each axle.
GVWR -- gross vehicle weight rating, the maximum weight on all the axles of the vehicle added together. This may be (and usually is) less than the sum of the GAWRs.
GCWR -- gross combined weight rating, the maximum total weight of the vehicle and and any towed trailers or cars or whatever.
If you have a trailer, the tongue weight would get included along with the weight of the vehicle and occupants and cargo against the GVWR. The total trailer weight is included against the GCWR.
A trailer hitch also has a weight rating (the maximum weight of a trailer that may be connected to it) and a tongue weight rating.