In the Sixth Chapter Lord Kṛṣṇa recommended how to practice yoga. Yoga is the beginning of linking up our lost relationship with the Lord, yoga. Yoga means adding, addition, or linking. Because we are now forgotten . . . the yoga system, any yoga system, means . . . bhakti-yoga, karma-yoga, jñāna-yoga—there are different names of yogas—but actual fact is how to link up our lost relationship with the Supreme Lord. That is called yoga. Yoga indriya-samyamaḥ.
Indriya. Because we are being deviated from our eternal relationship with God, Kṛṣṇa, on account of our too much being engaged in sense gratification. Bhogaiśvarya-prasaktānāṁ tayāpahṛta-cetasām (BG 2.44). Lord says, Kṛṣṇa says, "Those who are too much after bhoga and aiśvarya, material enjoyment and material opulence," prasaktānāṁ tayāpahṛta-cetasām, "whose heart has been taken away by the process of sense gratification, for them, it is very difficult to be situated in samādhi." Bhogaiśvarya-prasaktānāṁ tayāpahṛta-cetasām.
So yoga, yoga means to control the senses. Those who are too much in the bodily concept of life, for them, this haṭha-yoga is prescribed just to control the sense by some mechanical way. You sit down, āsana, prāṇāyāma, dhyāna, dhāraṇā, pratyāhāra—there are eight different stages of fulfilling the yoga practice—and then coming to the position of samādhi. Samādhi means fully situated in Kṛṣṇa consciousness. That is real samādhi.