I mean dead ones. I know there are lots of different types of live ones. But in the UK in a butchers you will generally only get organic, free-range and standard chickens and they're all about the same in size and age if not flavour and price.
Yesterday we bought a chicken to roast from our current favourite butchers in the Mission Food Hall on Mission at 22nd Street. The man who served me who I suspect is the manager very kindly took me through all the chickens on offer. They had frying chicken (that is a whole chicken not pieces) which apparently is young, tender but with not much meat so you can fry/barbecue the chicken. Then there's broiling which is a bit bigger I think. Then there were stewing hens which were huge, ex-layers, and older so suitable for casseroles. And finally there were roasters which were male, younger than the stewers and tender. I think that was it. I may have got a bit confused. There were also all the free-range/organic/basic options too within this. I think they also still sell capons here which I seem to remember are banned in the UK, but which I remember from my childhood. Thank God the staff in shops are so helpful because my bewilderment continues, and this all makes ethical shopping more confusing than ever.