Patañjali Yoga Sūtra-s has 196 aphorisms, classified under four chapters. First Chapter is known as samādhi pāda and has 51 aphorisms. Second chapter is known as sādhana pāda and has 55 aphorisms. These two chapters deal with the practice of controlling the mind and to enter into different stages of meditation. Third chapter is known as vibhūti pāda and has 56 aphorisms. This chapter deals with siddhis (super human powers) that we may acquire due to sincerity and intensity of practice, as explained in the first two chapters. Fourth chapter is known as kaivalya pāda and has 34 aphorisms.
We have covered chapters one and two through various articles on meditation. Now, we will take up for brief study, chapters three and four vibhūti pāda and kaivalya pāda.