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Chair

Written By: Elijah Baley

Reference
A chair is a piece of furniture with a raised surface used to sit on, commonly for use by one person. Chairs are most often supported by four legs and have a back; however, a chair can have three legs or could have a different shape.
A chair without a back or arm rests is a stool,or when raised up, a bar stool. A chair with arms is an armchair and with folding action and inclining footrest, a recliner. A permanently fixed chair in a train or theater is a seat  or, in an airplane, airline seat;[when riding, it is a saddle and bicycle saddle,  and for an automobile, a car seat  or infant car seat. With wheels it is a wheelchair and when hung from above, a swing.
A chair for more than one person is a couch, sofa, settee, or "loveseat"; or a bench.  A separate footrest for a chair is known as an ottoman,  hassock  or pouffe.