By definition, a couch is a seating arrangement with two armrests or none at all. They are tapered at the back to allow for cushioning. Couches have an internal frame that is upholstered with fabric and at times have a spring setting in both back and bottom. Whereas the term lounge is referred to a long chair. It is long enough to provide comfortable seating for a large number of people as compared to sofas and couches. Lounges also have an internal structure covered with upholstered fabric.