seats
Furniture designed for sitting.
step chair 
Chair whose foldaway lower part can be pulled out to form a step.
bench 
Long narrow unupholstered seat with or without a back, seating several people.
bean bag chair 
Seat composed of an upholstered bag; it assumes the form of the human body.
ottoman 
Low upholstered seat having neither arms nor back.
banquette 
Bench with an upholstered seat.