Fiber optic cables are thin strands of glass that carry digital information over long distances by transmitting light signals. They work by having the light bounce between the inner and outer surfaces of the glass fiber due to the difference in refractive index, which allows the light to travel along the fiber. Fiber optic systems have advantages over metal wire cables as they are less expensive, thinner, have higher carrying capacity, experience less signal degradation, use light signals, require low power, and can carry digital signals.