What is a GMC? Are observers and simulators discussing the same star-forming clouds?

As both simulations and observations reach the resolution of the star-forming molecular clouds, it becomes important to clarify if these two techniques are discussing the same objects in galaxies. We compare clouds formed in a high-resolution galaxy simulation identified as continuous structures within a contour, in the simulator's position–position–position (PPP) coordinate space and the observer's position–position–velocity space (PPV). …