The core concepts of yoga

From the Indian tradition: the limbs, principles and words the practice stands on.

Yoga योगYoga From the root yuj, to yoke or join: a discipline of body, breath and attention toward a settled, clear mind.
- The Eight Limbs अष्टाङ्गAṣṭāṅga The eight limbs Patañjali's Yoga Sūtra names, from conduct toward others to absorption.
  - Restraints यमYama The first limb: five restraints in how one treats others and the world.
    - Non-harming अहिंसाAhiṃsā Not harming any being, in deed, word or thought; in practice, also not forcing the body.
    - Truthfulness सत्यSatya Truthfulness in speech and action.
    - Non-stealing अस्तेयAsteya Not taking what is not freely given.
    - Moderation ब्रह्मचर्यBrahmacarya Right use of energy; often read as moderation or restraint of the senses.
    - Non-possessiveness अपरिग्रहAparigraha Not grasping or hoarding; taking only what is needed.
  - Observances नियमNiyama The second limb: five observances toward oneself.
    - Cleanliness शौचŚauca Cleanliness of body, surroundings and mind.
    - Contentment संतोषSaṃtoṣa Contentment with what is.
    - Discipline तपस्Tapas Steady effort; the heat of practice sustained over time.
    - Self-study स्वाध्यायSvādhyāya Study of oneself and of the texts.
    - Devotion ईश्वरप्रणिधानĪśvarapraṇidhāna Dedication of one's practice to something greater than oneself.
  - Posture आसनĀsana The third limb: a steady and easeful seat; in modern practice, the postures themselves.
  - Breath Regulation प्राणायामPrāṇāyāma The fourth limb: regulating the breath, its length, rhythm and pause.
    - Victorious Breath उज्जायीUjjāyī Breathing through the nose with a slight narrowing of the throat, making a soft, even sound.
    - Alternate Nostril Breathing नाडीशोधनNāḍīśodhana Breathing in and out through one nostril at a time, alternating sides.
    - Skull-Shining Breath कपालभातिKapālabhāti Short, active exhalations through the nose with passive inhalations; not for pregnancy or high blood pressure.
    - Bellows Breath भस्त्रिकाBhastrikā Forceful inhalations and exhalations of equal strength, like a bellows; learn it with a teacher.
    - Cooling Breath शीतलीŚītalī Inhaling through the tongue rolled like a tube, exhaling through the nose.
    - Humming Bee Breath भ्रामरीBhrāmarī Exhaling with a steady humming sound, the ears lightly closed.
  - Withdrawal of the Senses प्रत्याहारPratyāhāra The fifth limb: drawing the attention in from the senses.
  - Concentration धारणाDhāraṇā The sixth limb: holding the attention on one point.
  - Meditation ध्यानDhyāna The seventh limb: attention that flows unbroken toward its object.
  - Absorption समाधिSamādhi The eighth limb: complete absorption, where the sense of a separate observer falls away.
- Vital Energy प्राणPrāṇa The life force the tradition describes as moving with the breath.
  - Channels नाडीNāḍī The channels through which prana is said to flow.
    - Ida इडाIḍā The left channel, associated with the moon and with cooling.
    - Pingala पिङ्गलाPiṅgalā The right channel, associated with the sun and with heat.
    - Sushumna सुषुम्नाSuṣumnā The central channel along the spine.
  - Energy Centres चक्रCakra The wheels or centres the tradition places along the central channel.
    - Root मूलाधारMūlādhāra The root centre, at the base of the spine.
    - Sacral स्वाधिष्ठानSvādhiṣṭhāna The centre below the navel.
    - Solar Plexus मणिपूरMaṇipūra The centre at the navel.
    - Heart अनाहतAnāhata The heart centre.
    - Throat विशुद्धViśuddha The throat centre.
    - Brow आज्ञाĀjñā The centre between the eyebrows.
    - Crown सहस्रारSahasrāra The crown centre, at the top of the head.
- The Five Sheaths कोशKośa The five layers the Taittirīya Upaniṣad describes, from the body to bliss.
  - Food Sheath अन्नमयAnnamaya The physical body.
  - Breath Sheath प्राणमयPrāṇamaya The layer of breath and vital energy.
  - Mind Sheath मनोमयManomaya The layer of thought and feeling.
  - Wisdom Sheath विज्ञानमयVijñānamaya The layer of discernment.
  - Bliss Sheath आनन्दमयĀnandamaya The innermost layer, of bliss.
- The Three Qualities गुणGuṇa The three qualities Sāṃkhya sees in all of nature.
  - Clarity सत्त्वSattva Clarity, balance, lightness.
  - Activity रजस्Rajas Activity, passion, restlessness.
  - Inertia तमस्Tamas Inertia, heaviness, rest.
- Locks बन्धBandha Engagements of muscles that hold and direct energy in practice.
  - Root Lock मूलबन्धMūlabandha A gentle lift of the pelvic floor.
  - Abdominal Lock उड्डीयानबन्धUḍḍīyānabandha Drawing the lower belly in and up; in its full form, done on an empty stomach after exhaling.
  - Throat Lock जालन्धरबन्धJālandharabandha Lowering the chin toward the chest while the chest lifts.
- Seals मुद्राMudrā Gestures, usually of the hands, that shape attention in practice.
  - Salutation Seal अञ्जलिमुद्राAñjalimudrā The palms joined at the heart.
  - Seal of Knowledge ज्ञानमुद्राJñānamudrā The tips of the thumb and index finger touching.
- Gaze दृष्टिDṛṣṭi A fixed point of the gaze that steadies the attention in a pose.
- Linked Movement विन्यासVinyāsa Movement placed with the breath, one position to the next; also the short flow that links poses.
- Om ॐOṃ The sacred syllable, chanted at the start and end of practice.
- Hatha Yoga हठHaṭha The yoga of force: posture, breath, locks and seals, as the Haṭha texts teach.