Optical fibers are thin strands of glass or plastic that transmit light signals over long distances. They work by using the principle of total internal reflection, allowing light to bounce along the fiber without escaping. This technology is widely used in telecommunications, enabling high-speed internet and clear phone calls. In addition to telecommunications, optical fibers are also used in medical instruments, such as endoscopes, which allow doctors to see inside the body without major surgery. Their ability to carry large amounts of data quickly and efficiently makes them essential in modern communication and various industries.