First, depending on the number of optical fiber cores inside, cables are divided into "single-core cables" which contain only one core, and "multi-core cables" which contain multiple cores. The total number of cores for a 1pc fiber patch cable is calculated as the number of branches multiplied by the number of cores per branch (if there are no branches, the number of branches = 1). 5 microns that enables multiple light modes to be propagated. According to the laying method: self-supporting overhead optical fiber, pipeline optical fiber, armored buried optical fiber. There are multiple fibre optic cable types, and it is important to understand the differences between each one. Each has distinct advantages and will be suited to varying environments, applications, or industries. Some of the main types are explored below: In terms of bend and flex, glass optical. Optical fibers are mainly composed of three parts: the core, the cladding and the protective layer.