A couch and a sofa are similar pieces of furniture that are often used interchangeably; however, there are some key differences between them. A couch is a two- or three-seater piece of furniture that is usually larger than a sofa and may have a chaise lounge. It’s often upholstered with either fabric or leather and can be used for lounging and reclining. On the other hand, a sofa is a two- or three-seater piece of furniture with a more formal look and feel. It’s usually upholstered with fabric and is used for sitting. It can also have a chaise lounge, but it’s usually smaller than a couch.