The video comprehensively explains the Definition, Working, Uses and Applications of optical fibers. Optical fibers are long, thin strands of very pure glass about the diameter of a human hair. Normally they are arranged in bundles called Optical Cables. Optical fibers are used to transmit light signals over long distances. They work on the principle of Total internal reflection. An optical fiber consists of three layers; core, cladding and buffer coating. The optical cables are protected by a layer called Jacket. Optical fibers are used to transmit communication signals. They are also used in endoscope to view internal body organs and in photometers.