Adding an additional resource: http://changingears.com/rv-sec-tow-v...derstand.shtml
Short version: "Don't exceed any individual rating, even if the total is within limits. Actual weighing with a scale is the only way to know your numbers for sure. Don't trust printed or spoken information."
GVW: Gross Vehicle Weight
Your "all-in" weight. Vehicle/Trailer. People. Contents. Fluids. Everything.
GVWR: Gross Vehicle Weight Rating.
The max allowed GVW.
GCW: Gross Combination Weight
Total all-in weight of both towing vehicle and towed (trailer).
GCWR: Gross Combination Weight Rating
The max allowed GCW
GAW: Gross Axle Weight
Measured on each axle; the actual weight each axle is supporting.
The max allowed GAW.
The amount of weight transferred from the trailer and supported by the hitch. Should be 10-12% of trailer weight.
Too light or too heavy and vehicle/trailer handling will be affected.
A weight-distributing hitch transfers the same amount of weight to the vehicle, but the lever action moves some of the weight to the front axle rather than "all" on the rear axle. A WDH is also significantly heavier than a drawbar and needs to be part of your tongue weight calculation.
Curb Weight: "Unladen" vehicle weight.
Total vehicle weight with standard options/equipment, fluids, fuel, etc. No people or cargo.
Dry Weight: Similar to Curb weight, but without fluids, batteries, propane, accessories. etc. "Fresh from the factory without any dealer prep." Rarely used, other than by RV sellers to tell you "Sure, your car can handle that! (as long as you don't bring any water or personal items with you or actually want it to be useful. )" :P
All the extra stuff you add, including people.
Once you add a trailer, you are going to affect GAW, GVW and GCW. Tongue weight will transfer from the trailer to the vehicle. Note, you can have a negative tongue weight if poorly loaded. This will actually lift the rear of the tow vehicle.