The eight limbs are: yama, niyama, āsana, prāṇāyāma, pratyāhāra, dhāraṇā, dhyāna, and samādhi.

This sutra enumerates the eight (aṣṭa) limbs (aṅga) of yoga:

Yama: ethical restraints, the relationship with others. Niyama: personal observances, the relationship with oneself. Āsana: posture, work with the body. Prāṇāyāma: regulation of vital energy. Pratyāhāra: withdrawal of the senses. Dhāraṇā: concentration, fixing the mind. Dhyāna: meditation, continuous flow of attention. Samādhi: absorption, complete unification.

The first five are considered external (bahiraṅga); the last three, internal (antaraṅga).

Patañjali will dedicate the following sutras to explaining each one.