Pratyahara refers to the process of detaching oneself from one’s sensory surroundings. This can only be achieved when the focus of the mind is taken away from the numerous stimuli perceived by the sensory organs. Instead, the attention of the mind is turned inward. This allows the yogi to transcend the surroundings, and begin the third stage of Ashtanga yoga – the one that focuses on internal aspects. 

The internal aspects of yoga include "dharana", "dhyana" and "samadhi".