ThanksThe Stingray is the Corvette model name resurrected from the 60s and 70s model Corvettes. Beginning with the 2014 model year all Corvettes carried the "Stingray" name. The Z06 is an engine option, the LT4 which is supercharged. Super chargers are similar to Turbochargers, except Turbos are powered by exhaust gases flowing through to turn the compressing impeller, whereas, a Supercharger is turned by the engine itself. Along with the LT4 engine, the Z06 gets wide body components to cover the wider tires it gets. The Grand Sport model is just a base Stingray with the wide body panels to cover the wider tires and bigger brakes like those that the Z06 gets. It's basically a cross between the Base and the Z06...or it's a Z06 without the supercharged engine.....more or less.
So in reality, there are 4 models of Corvettes in the C7 variety.... Stingray (Base model), Grand Sport and Z06 and the ZR1 which has an even more powerful Supercharged engine.