Stock, Broth, Jus

Traditionally, stocks have the flavour and gelatinous collagen-y thickness that comes from cooking bones. Broth was cooked not with bones but with the meat itself. While a jus is a sauce made from the pan drippings, usually from a roast. This simple distinction I learned from Thomas Keller.

Now, you can also have vegetable stock, so some other useful distinctions between stock and broth include that, generally, stock is intended to be used in the preparation of another dish rather than eaten directly like broth. As such, you would more likely use whole vegetables in stock to impart the flavour, but still scoop them out afterwards, while a broth would have cut vegetables ready to eat in the broth itself.