Optical fiber jumpers (also known as optical fiber connectors) refer to the connector plugs installed on both ends of the optical cable to realize the active connection of the optical path; one end with a plug is called a pigtail. Fiber patch cords (Optical Fiber Patch Cord/Cable) are similar to coaxial cables, but without a mesh shield. At the center is the glass core where light travels. In a multimode fiber, the diameter of the core is 50 μm to 65 μm, which is roughly the thickness of a human hair. The diameter of the single-mode fiber core is 8 μm~10 μm. The core is surrounded by a glass envelope with a lower refractive index than the core to keep the fiber within the core. On the outside is a thin plastic jacket that protects the envelope.
The classification and overview of fiber optic patch cords are as follows

Optical fiber jumpers (also known as optical fiber connectors) are also optical fiber connectors that connect to optical modules. There are also many kinds, and they cannot be used with each other. The SFP module is connected to the LC fiber optic connector, while the GBIC is connected to the SC fiber optic connector. The following is a detailed description of several commonly used optical fiber connectors in network engineering:

①FC type fiber jumper

: The external reinforcement method is a metal sleeve, and the fastening method is a turnbuckle. Generally used on the ODF side (the most used on the patch panel)

②SC type optical fiber jumper: the connector connecting the GBIC optical module, its shell is rectangular, and the fastening method is the plug-and-pull type, which does not need to be rotated. (Most used on router switches)

③ST-type optical fiber jumper: commonly used in optical fiber distribution frame, the outer shell is round, and the fastening method is turnbuckle. (For 10Base-F connections, the connectors are usually ST type. Often used in fiber optic distribution frames)

④LC-type fiber jumper: a connector for connecting SFP modules, it is made with a modular jack (RJ) latch mechanism that is easy to operate. (commonly used by routers)