I'm back to page 30 on the meat birds section. I've been trying to understand more about hatchery = yeah they are chickens but... Rather than hatchery chicks = actually what to expect from that breed. It seems like hatcheries just mass produce so these chicks are technically from the same genes as the breed but they haven't been kept up. They've only been mass produced, rinse, repeat. Not kept to a standard really.
Hatchery birds are bred for egg production. You can not be guaranteed they are even pure lineage. When a "breed" that should have red ear lobes has white and red ears with a body that looks more like a Leghorn you start to suspect Leghorn was in it's lineage yet it's buff and looks somewhat Orpington as it's sold as. Hatcheries provide a service and people are very happy with the increased egg production. So you get a variety of different looking birds but they are not bred to their breed standard. They are bred with eggs in mind to fulfill the publics want.
Breeder stock are bred to the Standard of Perfection. Body type, i.e.- width of back and tail, breast development, standard weight and so forth that the Standard states is for that breed lends to the characteristic of the breed. If a dual purpose bird the wide back and tail is a physical trait that reduces egg laying capacity yet promotes fleshing. Note that breeds known for high egg production do not have the body type of dual purpose birds. Typically a narrow body with pinched tails.
Breeders do sell and ship chicks. It would be no different than ordering from a hatchery other than the price is more and if you did your homework on the stock being offered it will be of good quality. Bred to the standard. It's an upfront cost addage and for those that want a particular breed to maintain and work to the Standard of Perfection for that breed.