Here's what I have learned about broths and stocks.
A broth was typically a light preparation from meats or vegetables or both, intended as a soup, or a first course. Traditionally, in culinary terms, a broth didn't include bones, but now the word is more inclusive. A broth can also be made from ingredients like Parmigiano-Reggiano cheese - it's a delicious light first course or soup course.
A stock, on the other hand, is a foundation for use in cooking (gravies, soups, etc). Traditionally, stocks were not intended to be consumed like a soup, but were intended to form the base for a savory dish. Stocks contain bones.
Stocks are usually made by throwing the chicken carcass or the leftover beef rib bones (or lamb or veal or any meat) into a pot of water, and simmering it for a few hours, then straining it through cheesecloth to remove all the pieces. Vegetables may be added, and often are, as are herbs, in moderation. Bone broth is sort of a crossover, because it can be sipped like soup, or used as the base in lots of recipes.
A bone broth is a little more time consuming than a simple stock or broth, although not difficult. Bone broths provide us with gelatin (great for hair, skin and nails) and important minerals. Plus they're economical. Beef soup bones, leftover chicken bones, beef knuckles and marrow, chicken backs and necks, are often affordable, and homemade broths and stocks can save you a lot of money.
Bones, from poultry or beef or lamb, are placed on a large baking sheet with sides (just so liquids don't spill out of the sides) or even a large roasting pan. It's ok, and even preferred, if some of the meat remains attached to the bones. Chicken wings can be included, and the less useful parts like backs and necks (not livers or hearts or kidneys). For a beef bone broth, any meaty bones can be used. Beef marrow, the "knuckles", or beef soup bones are good.
Then, the bones are roasted until they turn a beautiful, deep, reddish-brown color (like mahogany) at about 425 degrees for about an hour. Then they're turned into a large pot of water and simmered for a long time (they need to simmer for hours, but they don't need any attention). Make sure to use a large pot, and don't add too many extras. Just some black pepper, or a small onion, maybe a carrot, and some fresh thyme. You're not making a vegetable soup, but a flavorful broth from bones.
I chill mine when it's simmered for several hours, or most of the day, by placing the pot in a sink filled with ice. When it's cooled, I fill heavy duty quart size freezer bags and lay them on a pan, flat, in the fridge. (Don't place hot broth in the fridge). Then when they're cold, I place the pan in the freezer and freeze them flat, so they can be stored upright, like books on a shelf. Just don't overfill the bags, so they will lay flat.
Here's an informative article that explains pretty much everything, including the health benefits, and a step-by-step on how to make a broth.:
http://nourishedkitchen.com/bone-broth/