The GVWR of 7200 lbs. is the maximum weight your truck can weigh, including the weight of the truck, passengers, and payload.
The tow capacity is the maximum of what your truck can pull....in your case 9700 lbs.
There is also a GCWR (Gross Combined Weight Rating). In your case, that is probably 15,400 lbs. That is the combination of your truck and everything in it, along with the trailer, and everything in that.....the total weight of every thing going down the road. If you are maxed out on your GVWR at 7200 lbs., then you should not tow more than a 8200 lb. trailer. (15,400 lbs. minus 7200 lbs.). Likewise if you are towing the maximum of a 9700 lb. trailer, then your truck should weigh no more than 5700 lbs.....that is pretty much empty except for a driver.
There are also RAWR (rear axle weight rating) and FAWR (front axle weight rating) that will be posted on the drivers door. Those 2 figures totaled should equal more than the GVWR, so you have a little leeway there. But it is important that when setting up your WDH (weight distributing hitch) that neither of those 2 figures are exceeded, also.
Hope those explanations are not too confusing.