Fiber Optic Cables

What do the fiber terms 9/125, 50/125 and 62.5/125 refer to?	Fiber Optic Cable

Fiber Cable Tutorial	Fiber Optic Termination- How to terminate fiber optic cable using Giganet Fibre Optic connectors

Fiber Optical Cable+ Splice Works

What do the fiber terms 9/125, 50/125 and 62.5/125 refer to?