There are three types of Feathering . Loose, close, and hard . it has to do, from what I understand ,about how closely the feathers lay to the skin.
A loose feathered bird would look like an Orpington ,fluffy .
A close feathered bird would be like a Sussex
A great Sussex judge and breeder once defined close feathered as plumage which does not lift up from the body with every puff of wind against the lay of the feathers.
Then there's hard feathered, like the game birds . where the feathers lay real close to the skin .
Karen