Acharya Prashant explains that the essence of both Knowledge Yoga and Action Yoga is centered on the 'I' or the ego. The ego is inherently incomplete and seeks union to fulfill its sense of lack. Knowledge Yoga involves the ego abandoning the very notion of its existence, realizing that it is not the doer and that all actions are performed by nature. In this state, one remains a non-participant in actions, resting in the self as the witness. This path requires a complete renunciation of the doer-ship, recognizing the self as the infinite and satisfied soul that has nothing to gain or lose.