This is more complex than joining electrical wire or cable and involves careful cleaving of the fibers, precise alignment of the fiber cores, and the coupling of these aligned cores. For applications that demand a permanent connection a fusion splice is common. It's composed of several parts such as the cable core, reinforced steel wire or other strength member, filler and sheath. In addition, there are components such as water blocking materials. An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers are widely used in fiber-optic communication, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than. Right now, fiber internet has the fastest plans and symmetrical speeds, but that's probably going to change in the next several years as cable internet incorporates new technology enabling multi-gig symmetrical speeds. Plus, it's more widely available than fiber. Overall, cable and fiber are both. Fiber uses light through glass (fiber optic) cables, while cable uses electrical signals over coaxial copper. That difference is why fiber is typically faster, more reliable, and delivers lower latency, especially during peak hours.