The chickens we know today are the descendants of Red Junglefowl, first domesticated in Asia at least five thousand years ago. Today, chickens are kept all over the world for their eggs and meat. There are more chickens on the planet than any other bird, making them the most common and widespread domestic animal.
What to Call Chickens
Adult female chickens are referred to as hens, while adult males are called roosters. When chickens are less than a year old, the females are called pullets and the males are called cockerels. A very young, recently hatched chicken is called a chick regardless if it is male or female.
Types of Chickens
Chickens can be separated into four broad categories by their purpose. Layers are chickens that excel at laying eggs, while meat birds are great at converting feed into a plump meaty carcass that can be used for food. Dual purpose chickens are ones that may be used for either egg or meat production. Finally, fancy chickens are kept for their looks, and may neither be prolific egg layers nor useful for meat production.
Chickens can also be classified by their bloodlines. Purebred chickens belong to a specific breed. Mating a rooster and hen of the same breed will give you baby chicks of the same breed. Purebred chickens are often referred to as heritage chickens. If you mate a rooster and hen of two different breeds, the offspring are referred to as hybrid chickens. There are many reasons to raise hybrid chickens. It is common for first generation hybrid chickens to have accentuated qualities of their parent stock. Hybrid chickens are some of the most prolific egg layers. On the down side, you cannot mate two hybrid chickens to reproduce baby chicks similar to their parent stock. The only way to produce consistently similar hybrids is by crossing the same breed rooster with the same breed hen.
While chickens can come in various sizes, they can be generally lumped into two categories: large (or heavy) and bantam. Bantam birds are smaller versions of a particular breed. Many breeds can be found in both large and bantam varieties.