Optical fibers transmit light signals over long distances through the process of total internal reflection. They were first developed in the 1850s but were not widely used until the 1970s. Optical fibers have several advantages over copper wires including higher bandwidth capacity, less signal degradation, and greater security. They are now commonly used for telecommunications, broadband internet, and other applications. While more fragile than copper, optical fibers have lower installation costs due to their small diameter and are becoming increasingly important for data transmission.