Patanjali Yoga Sutras mention Samadhi and Samapatti, what is the difference between them?
I am referring to the following excerpt from the Raja-Yoga by Swami Vivekananda:
When, by the previous preparations, it becomes strong and controlled, and has the power of finer perception, the mind should be employed in meditation. This meditation must begin with gross objects and slowly rise to finer and finer, until it becomes objectless. The mind should first be employed in perceiving the external causes of sensations, then the internal motions, and then its own reaction. When it has succeeded in perceiving the external causes of sensations by themselves, the mind will acquire the power of perceiving all fine material existences, all fine bodies and forms.
This stage of perceiving the supernatural forms is called Samapatti :
Samāpatti stands for correct (samyag) acquisition (āpatti) of Truth. It is a form of alaukika-pratyakṣa (extraordinary perception) forming thus a legitimate part of the perceptual (pratyakṣa) instruments of adequate knowledge (pramāṇa). Reference : https://en.m.wikipedia.org/wiki/Samāpatti
But the yogi is still away from his ultimate goal. Swamiji writes:
When it can succeed in perceiving the motions inside by themselves, it will gain the control of all mental waves, in itself or in others, even before they have translated themselves into physical energy; and when he will be able to perceive the mental reaction by itself, the Yogi will acquire the knowledge of everything, as every sensible object, and every thought is the result of this reaction. Then will he have seen the very foundations of his mind, and it will be under his perfect control. Different powers will come to the Yogi, and if he yields to the temptations of any one of these, the road to his further progress will be barred. Such is the evil of running after enjoyments. But if he is strong enough to reject even these miraculous powers, he will attain to the goal of Yoga, the complete suppression of the waves in the ocean of the mind. Then the glory of the soul, undisturbed by the distractions of the mind, or motions of the body, will shine in its full effulgence; and the Yogi will find himself as he is and as he always was, the essence of knowledge, the immortal, the all-pervading.
This is called Samadhi, which are of two types,
Samprajnata (When the mind completely dissolves in Brahman inspite of having the sense of the difference between knower, knowing and object of knowledge(jnaataa, jnana and jneya. Reference: Yogiguru by Paramahansa Nigamananda, page 71) and Asamprajnata(Where the mind dissolves completely in Self with Triputi-bheda ie perfect absence of any difference between the above three.(Ibid, page 71).
On Asamprajnata Samadhi, Swami Vivekananda writes:
Then will all sorrows cease, all miseries vanish; the seeds for actions will be burnt, and the soul will be free for ever.
I am adding something about the annihikation of non-sattvik vrittis:
योगश्चित्तवृत्तिनिरोधः - Patanjali Yogasutra 1.2
Yoga is known as the nirodha of the chitta-vrittis. The non-sattvik vrittis make the mind always restless like we can not see the bottom of a pond when the water is wavy and unclean. They make us deviate from our Own Self. The path of yoga is to clean the chitta of all such vrittis and make it still so that it becomes perfectly transparent and one can see the Self without any hindrance. (Reference: Yogi-Guru, Nigamananda Paramahansa, page 26-27).