The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck, to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with either nylon or steel strings. Some modern guitars are made of polycarbonate materials. Guitars are made and repaired by luthiers. There are two primary families of guitars: acoustic and electric.