Chickens lay the eggs most commonly sold as chicken eggs. The domestic chicken is one of the world’s most widespread domesticated birds and is kept for both eggs and meat.
Modern chickens descend primarily from the red junglefowl of South and Southeast Asia. Selective breeding produced laying strains that can produce many more eggs than wild relatives. Eggshell color varies among breeds, but white and brown shells are especially common in commercial markets.
Other farm birds also lay edible eggs. Ducks, geese, quail, and turkeys can all be raised for eggs, but their eggs are less common in global supermarkets. The phrase “chicken egg” identifies both the animal source and the usual commercial product.