A chair is an inanimate object designed and manufactured with the sole purpose of providing humans with a place to sit. We have decided that a particular configuration of matter is used for this purpose, and when it is used as such, it is defined as a chair. A chair is a type of seat, typically designed for one person, and consists of one or more legs, a flat or slightly inclined seat, and a backrest. They can be made from wood, metal, or synthetic materials, and can be padded or upholstered in various colors and fabrics.
An armchair has armrests attached to the seat; a recliner is upholstered and has a mechanism that lowers the back of the chair and lifts a footrest in place; a rocking chair has legs attached to two long, curved slats; and a wheelchair has wheels attached to an axle under the seat. Chair sliders are attached to the feet of the chairs to prevent them from scratching or catching on the floor. Designers who sit on tall easels will use a designer chair; it will usually have an additional height. In Europe, largely due to the Renaissance, chairs ceased to be a state privilege and became standard furniture for anyone who could afford them. These chairs are designed for tasks that require extended periods of sitting time, such as receptionists or supervisors of control panels.
In rare cases, chairs are made from unusual materials, especially as a form of art or experimentation. All chairs in the everyday world are imperfect examples of the perfect form of a chair that exists in the intelligible world of forms. The first images of chairs in China come from murals and Buddhist stelae from the 6th century, but sitting on chairs at that time was rare. Therefore, in some chair designs, the armrest is not continuous to the back of the chair, but is missing in the elbow area. If combined with a sliding chair, the ottoman can be mounted on tilting arms so that it sways back and forth with the main glider. In the past, chairs were covered with fabric or leather, were made of carved wood, and were much lower than current chairs; chair seats were sometimes only 10 inches (25 cm) tall.
The actual dimensions of the chair are determined by measurements of the human body or anthropometric measurements.