What is the Propagation?

What is the meaning of propagation?

Propagation has different meanings and different senses in different contexts. Generally it refers, to carry from place to place, to disseminate or to produce etc. But in Computer Science and Physics it refers to the movement of a wave through a medium. In the context of your lectures (Propagation Modes of Fiber Optics), it refers to the movement of light ray(s) through fiber optics.