Fiber optics use thin strands of glass or plastic to transmit light signals over long distances. Light signals are produced by a transmitter and sent through the optical fiber, where they are received and decoded by a receiver. Along the way, a regenerator may be needed to boost weakening signals. Fiber optic systems have advantages over metal wires like lower costs, higher data capacity, and less signal degradation during transmission. Optical fibers are made by drawing thin fibers from a heated glass preform and testing them to ensure quality.