Yoga2

Yoga, as a disciplined method for attaining a goal;
Yoga, as techniques of controlling the body and the mind;
Yoga, as a name of one of the schools or systems of philosophy (darśana);
Yoga, in connection with other words, such as "hatha-, mantra-, and laya-," referring to traditions specialising in particular techniques of yoga;
Yoga, as the goal of Yoga practice."
According to David Gordon White, from the 5th century CE onward, the core principles of "yoga" were more or less in place, and variations of these principles developed in various forms over time