In the restaurants I've worked in, and cookbooks that I have frequented, the difference is:

Broth = Flavorful stock from animal products, veggies, and herbs that can be consumed on it's own or with the addition of other ingredients in a soup. Can be a base ingredient as well and used as a stock with the exception of consomme (certain veggies will not clarify enough). Defatting and fine-filtering is optional.

Stock = Unflavored, usually unsalted, cooked down meat sources (usually just marrow) and vegetables (optional and usually excluded) for use in consomme, gelatin, and base for broths/soups/sauces/risoto. Also used to add body to an existing broth or soup. Defatting (chill-skimming) and fine-filtering is usually mandatory.

Consomme = Stock that has been flavored, then clarified (with the use of eggs, irish moss, and other agents) to make a very clear, very rich, gelatinous soup.

There are not fixed definitions for these terms broth and stock.

The reason the term "bone broth" is almost universally used by in the paleo world, at least in the US, is I think almost entirely due to the influence of Sally Fallon and the Weston A. Price foundation.

http://www.westonaprice.org/food-features/broth-is-beautiful

They have been going on about it for a long time and as they usually use the term bone broth, people have picked up the term from them.

To be more confusing here in Britain a "broth" is used to mean a meat or fish soup usually with barley, rice or pulses added to it. A bone broth would be called a stock here.

Bone broth has alliteration going for it.

Very simple: Stock is something refined that a cook produces in a kitchen. Broth is something far more primeval that a caveman would produce over an open fire...after tearing the meat off the bones with his teeth.

Stock is for wimps. Broth is for Groks.

Okay, I disagree with all the previous answers! :-))

The traditional stockpot was a mixture of bones and vegetables--all edible food scraps, basically. Here on PH, people use the term bone broth because they don't always add vegetables--they may cook and drink it as pure meat broth.

In my case, I call mine bone broth stew because after the first 8 hours of simmering meaty bones I do add vegetables. I use large quantities of marrow bones so my broth is more dense (and fatty) than traditional stock. And I usually add additional vegetables as I work through the broth and meat.

I used to be confused about this and so are many recipes, websites. But I think Wikipedia has done a good job:

http://en.wikipedia.org/wiki/Broth More liquid, water based that may have bone, but almost always has some meat except vegetable broth which is really inaccurate and relatively new because broth traditionally always had some animal parts

In the US some cooking schools make broth from meat vs. stock from bones.

http://en.wikipedia.org/wiki/Stock_(food) More likely to have bones and connective tissue so more gelatinous.

I think both are tasty and have their uses, but nutritionally which is better? I guess it depends what type of nutrition you are looking for - more collagen, minerals, etc?

I think bone broth came about as a distinction for "modern" cooks who never knew how to make a stock or broth. Not too many people out there in the general public eating the SAD diet know that a broth is made with bones. They think bones are waste products to be thrown away or given to their dog. Thats why its almost impossible to buy meat in the grocery store with a bone in it or any fat on it either.

Not all stock is bone broth, but all bone broth is stock.

Perhaps technically there is some difference (according to what authority?), but I've always thought of stock in relation to cooking and broth in relation to taking it by itself or in a soup.

I think this is one of those hip-hop vs. rap questions where you ask ten people and get ten wildly different answers.

Stock = meat & broth = bones.

I would say that stock is reduced broth. Broth is what you'd actually drink, but if you boiled it down to make something more concentrated to store add to another meal that would be stock.

I think they're fundamentally the same. It's kind of like an outer garment can be called a jacket or a coat or even a parka. We could make a new amalgam - stroth? or bock? In the stone age, I think they used rocks instead of bones; that would be stone soup. Yum. Think of all the minerals.

I think some people like how the phrase sounds, that's all (all primal and whatnot). Personally, it creeps me out a little. I prefer to think of it as a very hearty stock.

There is one distinction, though. Generally, stock is made by cooking the tissues, bone, etc.. for 4-6 hours, but what people are calling "bone broth" is cooked far longer than that (12+ hours), often with a source of acid (such as wine or vinegar) to soften up the bones. The idea being that the broth is then a source of calcium which has been leached from the bones.

I have been doing a pork broth but i dont find that it is appealing to drink like soup. Does anyone have a really savory and flavorful recipe?

Broth= Has also meat for flavor and ofcourse bones (along with aromatics. Stock= has only bones or vegs This is how read it up somewhere

I add all my scrap and trimmings to my broth and usually i brown some ground meat, mostly beef heart now. Used to use ox tail but i think thats colossal waste of great braising meat. Broth without meat tastes only bones to me. Particulary if you cook the bones too long.

confused now after reading than befor reading? both bone broth and bone stock are the same thing. so sayith the cook. the cook is like the captain of a ship. the cook has the last word.

From Nourishing Traditions:

"The words "broth" and "stock" are used interchangeably in many cook-books, and for good reason, because the differences between the two are hair-splittingly small. In general usage "broth" is a home-cooking term, while "stock" is the province of professional kitchens. Broth is made from spits and spots of leftovers, and its nature changes according to what's on hand. Stock follows a prescribed formula. It is made on a regular basis and forms the groundwork for all of the sauces, soups and simmerings that are the mainstays of a classic kitchen.

There is yet another distinction. The meaty element of stock is predominately bone, while broth is typically made with meat. This difference changes the finished products in two significant ways. The large proportion of bone gives stock a more gelatinous texture and greater clarity. Broths tend to be thinner and cloudier.

Essential to all broths is starting with cold water. As the ingredients warm in the water, their fibers open slowly, releasing their juices to add flavor. Off flavors can result if the broth is not skimmed.

The broth must be kept at a bare simmer throughout the cooking process to ensure clarity."

Andrew Schloss,
The Washington Post