A tonearm is a crucial component of a turntable, responsible for holding the cartridge and stylus that read the grooves of a vinyl record. It pivots over the record's surface, allowing the stylus to track the grooves and convert the mechanical vibrations into electrical signals, which are then amplified to produce sound. Tonearms come in various designs, including straight and S-shaped types, each affecting sound quality and tracking ability. Proper setup and alignment of the tonearm are essential for optimal performance, ensuring that the stylus maintains consistent contact with the record while minimizing wear and distortion.