What really Sekha means?

i'm still a bit confused, i know that "sekha" means literally "a learner; in course of perfection" but in some article "sekha" means "a pupil or one under training in a religious doctrine." what i really want to know is if whether the word "sekha" is used for religious terms only, or it can be used in many terms, for ex. student at school or disciple from someone else to reach knowledge or something like that?