Individual coated fibers (or fibers formed into ribbons or bundles) then have a tough resin buffer layer or core tube (s) extruded around them to form the cable core. Several layers of protective sheathing, depending on the application, are added to form the cable. A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable but containing one or more optical fibers that are used to carry light. They have a central core surrounded by a concentric cladding with slightly lower (by ≈ 1%) refractive index. Optical fibers are typically made of silica with index-modifying dopants such as GeO 2. In addition to this, they find great use in data centers, telecommunications infrastructure, and enterprise networks; knowing their structure guarantees proper deployment and a. Cable provides protection for the optical fiber or fibers within it appropriate for the environment in which it is installed. Fiber optic "cable" refers to the complete assembly of fibers, other internal parts like buffer tubes, ripcords, stiffeners, strength members all included inside an outer. Fiber optic cables have revolutionized the field of modern communication by transmitting data over long distances with incredible speed and accuracy.