What's the difference between store bought free-range chicken (or beef) broth and the "bone broth" that everyone talks about and is supposed to be so healing?
I'm not sure here, but I would imagine store-bought broth is just that -- broth. When we say "bone broth," we're actually talking about a stock, which is typically made from simmering the bones for a long time at a low temp to extract all the minerals and gelatin.
Broth is usually just made from the meat and wouldn't have the same nutrient content as a traditionally made stock from bones.
I think canned/boxed broth is good in a pinch if you don't have the real thing in the freezer, especially if you just need it for color/flavor. But for health/nutrition, I don't think the canned or boxed stuff has anywhere near the healing properties of the real deal.
The reason they call chicken soup "Jewish penicillin" is, I think, because when it's made the traditional way, it'll have all the gut-helpful gelatin and easily absorbed/bioavailable minerals. Not so much with the stuff in a can, no matter how "fancy" it is (organic, free-range, no MSG, etc.) I don't think too many mass-marketing companies are taking the time to do it old-school.
Broth is made by boiling meat & veggies with no bones. Bone broth is more properly known as stock and is made by boiling bones along with the meat & veggies.
I think it's a question of getting the most nutrients out of your broth/stock.
When it's made at home, you are (more) sure of where the bones came from, that your broth contains marrow and other nutrient-dense minerals.
The storebought stuff is a big question mark since you can't be sure how the stuff was made.
A good bone broth will slightly gel (the amount of gelling will depend upon how much water is in it) in the fridge. A store bought broth was made without much or any cartilage, and will NOT gel in the fridge but will be absolutely liquid.
Which is fine, perhaps, but the bone broth, homemade, is going to be better and more nutritious.