As in horse breeding, a male kept for purposes of breeding is called a stud. His female counterpart, the female kept for producing kittens, is a brood queen. As is true of humans, horses and other mammals, a stud cat can father a lot more kittens in his lifetime than any brood queen can give birth to. (He can mate almost constantly, while the female can’t give birth constantly.)
Both studs and brood queens are chosen for their overall health, appearance and temperament. Neither is, of course, an ideal pet, as the female’s caterwauling while in heat is very unpleasant, as is the unneutered tom’s knack for spraying urine and fighting. Breeders construct “stud homes,” pens situated outdoors or in an indoor area away from the human living area, as the home of stud cats is going to take a lot of wear (and stench) from tomcat urine.