The mode of fiber patch cables indicates how light beams travel within the fiber. There are two fiber cable modes: single mode and multimode.
Single mode fiber patch lead only allows one mode of light to pass along its length with a very thin diameter of 8-10 microns, thus it can carry signals at much higher speeds with lower attenuation. Single mode fiber has two varieties: OS1 and OS2, which are different in construction and application. In Comparison Between OS1 and OS2 SMF Cables, the differences between OS1 and OS2 are illustrated. In general, OS1 and OS2 are both applicable for long-haul transmission but OS2 is more suitable for long-haul transmission by offering better performance with fewer losses.
The core of the multimode fiber patch cord is bigger, typically 50 or 62.5 microns, which enables multiple light modes to be transmitted. It comes in five varieties supporting different transmission rates or distances: 62.5-micron OM1, 50-micron OM2, 50-micron OM3, 50-micron OM4, and 50-micron OM5, which can be differentiated by standard jacket colors. Since multiple light paths travel down the cable, the distance which multimode fiber jumpers can reach is usually short. For short-distance transmission within a building or campus, multimode fiber patch cords are the best-suited type. You can get more information about multimode patch cables in Multimode Fiber Types: OM1 vs OM2 vs OM3 vs OM4 vs OM5.