यम-नियमासन-प्राणायाम-प्रत्याहार-धारणा-ध्यान-समाधयोऽष्टावङ्गानि ॥

yama-niyamāsana-prāṇāyāma-pratyāhāra-dhāraṇā-dhyāna-samādhayo'ṣṭāvaṅgāni

Yama, Niyama, Āsana, Prānāyāma, Pratyāhāra, Dhāranā, Dhyāna, and Samādhi are the eight limbs of Yoga.

In plain words: Yoga has eight parts, or limbs. They are: Yama (moral restraints), Niyama (personal disciplines), Asana (posture), Pranayama (breath control), Pratyahara (drawing the senses inward), Dharana (concentration), Dhyana (meditation), and Samadhi (complete absorption).