Broth

Broth is a savory liquid made of water in which bones, meat, fish, or vegetables have been simmered. It can be eaten alone, but is most commonly used to prepare other dishes such as soups, gravies, and sauces.

Commercially prepared liquid broths are available, typically for chicken broth, beef broth, and vegetable broth. In North America dehydrated meat stock, in the form of tablets, is called a bouillon cube. Industrially produced bouillon cubes were commercialized by Maggi in 1908 and by Oxo in 1910. Using commercially prepared broths allows cooks to save time in the kitchen.

Many cooks and food writers use the terms broth and interchangeably, and even when distinctions are made, they often vary from person to person.

However, a traditional distinction between stock and broth is that stocks are made primarily from animal bones, as opposed to meat, and therefore contain more gelatin, giving them a thicker texture. Another distinction that is sometimes made is that stock is cooked longer than broth and therefore has a more intense flavor. A third possible distinction is that stock is left unseasoned for use in other recipes, while broth is salted and otherwise seasoned and can be eaten alone.

Bouillon is the French word for "broth", and is usually used as a synonym for it.

Broth has been made for many years using the animal bones which, traditionally, are boiled in a cooking pot for long periods to extract the flavor and nutrients. The bones may or may not have meat still on them.

Egg whites may be added during simmering when it is necessary to clarify (i.e., purify, or refine a broth for a cleaner presentation). The egg whites will coagulate, trapping sediment and turbidity into an easily strained mass. Not allowing the original preparation to boil will increase the clarity.

...
Wikipedia