This article explains the core differences between OS1 and OS2 singlemode fibers, as well as OM3, OM4, and OM5 multimode fibers—to help OEM clients, installers, and data center engineers make informed decisions. There are different types of fiber optic cables because each type is optimized for specific applications that have unique requirements for bandwidth, transmission distance, and environmental factors. Unlike copper cables, which depend on electrical signals, fiber leverages light to convey. Digital Light Signals – Lasers inside the equipment generate the light that the fiber cables carry. Breaking them apart makes projects much easier to reason about: 1) Transmission mode and core size.