A couch is an upholstered item of furniture for the comfortable seating of more than one person and typically has an armrest on either side. Couches are usually to be found in the family room, living room, den or the lounge. They are covered in a variety of textiles or in leather.
The most common types of couches are the "loveseat" (or British two-seater) and the settee or sofa (two or more seats). A sectional sofa (often just referred to as a "sectional") is formed from multiple sections (typically 2 to 4) and usually includes at least two pieces that join at an angle of 90 degrees or slightly greater.
Other couch variants include the divan, the fainting couch (backless or partial-backed), the chaise longue (long with one armrest), the canapé (an ornamental 3-seater), and the ottoman (generally considered a footstool). To conserve space, some sofas double as beds (sofa-bed, daybed, or futon). There are also couches known by genericized trademarked names, such as a davenport or Chesterfield (named for the Earl of Chesterfield). Lofabed (low-fa-bed) a combination of a davenport base and futon mattress resulting in a more comfortable, practical, and economical alternative to the traditional sofa-bed.
The term three-piece suite describes a furniture set consisting of a two-/three-seater couch, plus two armchairs.
The term chesterfield is a Canadian term equivalent to couch or sofa.
The Sofa can be traced back to ancient Egypt of around 2000 BC, but the true sofa was invented in the end of the 16th to the early 17th century. At that time, horse hair, bird feather, plant villi such as natural flexible materials were made as the filler, with the outside velvet, embroidery, or other fabrics masked, to form a soft sofa surface. In Europe, the most popular Farthingle chair is one of the earliest sofa chair. Springs started to be used to support the sofa in 1828. In 1904, Morris invented the pocket spring. He grouped pocket springs into a sofa wooden framework to make the original modern spring sofa. In the 1920s, Dunlop created a new pad technology–rubber foam. Filling the gas in the natural rubber latex, forming into the mold and trying, at last he got a flexible filler - rubber foam. The application of foam rubber greatly simplified the process of filling masked, also had same appearance and quality. In the 1960s, people developed inflatable and water cushion sofa success, which indicates the sofa manufacturing technology was mature.