The chicken (Gallus gallus domesticus) is a domesticated form of the red junglefowl (Gallus gallus), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is one of the most common and widespread domesticated animals in the world. Chickens are primarily kept for their meat and eggs, though they are also kept as pets.[1]
The red junglefowl (Gallus gallus), also known as the Indian red junglefowl (and formerly the bankiva or bankiva-fowl), is a species of tropical, galliform bird in the phasianid family, found across much of Southeast and parts of South Asia.
A species (pl. species) is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. It can be defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction.
https://en.wikipedia.org/wiki/Chicken
https://en.wikipedia.org/wiki/Red_junglefowl
https://en.wikipedia.org/wiki/Species