Definitely not a well known product name, as someone who plays PC games and also does some CUDA development, I've never heard of this product from Nvidia.
I never heard of it. After looking it up, I don't get the appeal. Not sure why someone would want to take fancy screenshots of video games unless they're marketing a game.
Nothing gets my blood boiling like a Steam/App Store game listing that only has these "in-engine but not the actual gameplay" screenshots. If it's a FPS, show me the screen with the gun and the crosshairs. Show me the HUD in a driving game, the position of the camera in a 3rd person RPG. I don't care how some random NPC or a building looks from a position I'll never get the camera to when playing the game.
Photography, just like in the real world, but with lovingly-sculpted virtual worlds and (often) the ability to pose the actors in the scene as you wish. Dead End Thrills [0] is a master of this, both artistically and commercially, but much of his prior content seems to be down, which is a real shame.