An optical fiber, also known as an optical fibre in Commonwealth English, is a flexible glass or plastic fiber that can transmit light from one end to the other. Optical fibers are used in fiber-optic communications, where they permit transmission over long distances with low attenuation compared to electrical cables. They are also used for short-distance connections between devices, such as in high-definition televisions that offer a digital audio optical connection. Optical fibers consist of a core surrounded by a transparent cladding material with a lower index of refraction, which keeps light in the core by the phenomenon of total internal reflection, causing the fiber to act as a waveguide. Glass optical fibers are typically made by drawing, while plastic fibers can be made either by drawing or by extrusion. Optical fibers are used in computer networking, broadcasting, medical scanning, military equipment, and many other applications.