F is for farm or feral.
Many farm cats are feral cats.
Feral cats are domestic cats (housecats) who have returned to a wild state; either they were born and raised without significant human contact, or they were abandoned to the outside world.
Farm cats are cats who live outside and are expected to keep the rodents out of the cattle feed or similar products for crop farms.
Many farm cats are feral cats, but some feral cats live in town or in cities. Some farm cats may be better classified as strays.
My grandmother and her friend were abandoned when the previous people moved out of the red house. When the next people moved in, they were still around. Those people decided they would rather deal with cats than rats, so they decided to feed them. (The dogs decided Mama and my Grandma should eat in the shed instead of the porch.) These cats did a good job of hunting, and in training their kittens to hunt, although the what to hunt question did not always have the answer the humans might have preferred.
Some of the shed cats were not friendly. Old Mister Gray only let the humans pet him the last week before he died; we still are not sure if he could see at that point. Parker and Butler's father Beardy Cat ran to the other part of the shed when the human came inside, and left shortly after Parker and Butler were born. Führerlein had a moustache like the German dictator and was mean to other kitties who tried to eat next to him in the same or adjacent bowl.
In many cases, feral cats can be trapped, spayed or neutered as appropriate, and then released to their previous homes. These cats still take care of excess mice like before, but do not contribute to kitty overpopulation. TNR works to keep the populations of cats and their prey in check. When our human's old hometown made it illegal to feed ferals, the rabbit population boomed. Parker, Butler, Inky, and Truffles were TNR'ed at Protect Every Pet (they only had room for two more spays that day), but they got to keep their ears. Often, an altered cat is marked on the ear (during surgery) so that it is clear that the cat is fixed and has a human that cares for it at least enough to do that. Feral cats who have never been inside can get really scared in a shelter environment, and may never find an inside forever home; TNR or barn cat programs are their only hope.
We were socialized at an early age, and we knew our human's lap. It was easy for Parker to transition to being an inside cat.