Fiber to the x (FTTX) (also indicated as Fiber to the x) or fiber in the loop is an abbreviation and a term for any broadband network that uses optical fiber to give all or part of the local loop implemented for last mile telecommunications. Fiber optic cables can ensure much more data than copper cables, especially if we consider long distances.

FTTX is the common abbreviation for several configurations of fiber networks, that can be organized in two groups: FTTP/FTTH/FTTB (Fiber the premises (home or building)) and FTTC/N (fiber to the node, with copper wires completing the connection).