Eight Limbs of Patanjali Yoga

Ashta means eight and thus the term Ashtanga Yoga. The eight limbs are Yama, Niyama, Āsana, Prāṇāyāma, Pratyahara, Dhāraṇā, Dhyāna and Samādhi
The first two limbs are the Yamas and Niyamas. They are the do's and don'ts of Ashtanga Yoga. The Yamas and Niyamas are broken down into five subcategories. The five Yamas are Ahiṃsā, Satya, Asteya, Brahmacārya and Aparigraha and the five Niyamas are Śauca, Santoṣa, Tapas, Svādhyāya and Īśvarapraṇidhāna.
The five Yamas are the don'ts. Ahimsa is non violence to oneself and others. It is the source of vegetarianism. Satya is truthfulness or non lying. Asteya is non stealing. Brahmacārya is non promiscuity. Aparigraha is non greediness.
The Niyamas are the do's. Śauca is cleanliness. Santoṣa is contentment. Tapas is asceticism. Svādhyāya is self reflection. Īśvarapraṇidhāna is contemplation on the Divine.
The third limb is Āsana. It is where the practice of Hatha comes in to Ashtanga Yoga. Hatha Yoga prepares one to sit comfortably for long periods of time in order to contemplate the Divine.
The fourth limb is Prāṇāyāma. It is breath control. Ashtanga Yoga utilizes ujjahi breathing as part of the practice. It is done through the nose with restriction in the back of the throat to create a sound similar to snoring. The mula bandha is engaged to raise the kundalini and create heat.
The fifth limb is Pratyāhāra. It is focusing the attention within. It is done in Ashtanga Yoga through the Dristi or concentration of the visual focus or gaze.
The sixth limb is Dhāraṇā. It means concentration. In Ashtanga Yoga one is concentrating on doing the ujaiha breath, holding the bandhas, fixing the dristi or gaze and coordinating the breath with the movements.
The seventh limb is Dhyana. It is contemplation on ones chosen deity or Ishta Devata.
The eighth limb is Samadi. It is the ultimate goal of Yoga. Becoming One with all.