Single mode and multimode fiber differ in how light travels: single mode uses a narrow core and a single laser signal for long-distance, high-bandwidth performance, while multimode uses a larger core and multiple LED signals that excel over shorter runs. Although both carry data through light signals, they differ significantly in transmission mechanism, bandwidth-distance capability, deployment cost, and typical. There are two main types of fiber optic cables: single mode and multimode. Distance is the deciding factor, with single. Whether you are expanding a data center, upgrading an enterprise LAN, or building long-distance backbone connections, choosing between single mode fiber (SMF) and multimode fiber (MMF) is one of the most important design decisions. The basic structure consists of a central transparent core where the light travels and an outer layer called the cladding. The performance of the transmission, including speed and distance.