I'm confused. Seems they are all the same???

 

Stock is the boiled protein bones with mirepoix (carrot/onion/celery) reduced to the desired consistency, broth is the strained and seasoned stock for soup base or stew (or whatever else you want it for) and consomme is a mixture of ground meats, tomatoes, egg white and mirepoix. The egg protein causes a raft to form on the surface of the boiling liquid so that the impurities and oils can be captured and skimmed from the liquid. Essentially, it's a clarified stock, but richer as the actual meats are being used, not just their bones.