Kriyā

 (क्रिया) most commonly refers to a "completed action", technique or practice within a yoga discipline meant to achieve a specific result.

Etymology
is a Sanskrit term, derived from the Sanskrit root, meaning 'to do'.  means 'action, deed, effort'. The word karma is also derived from the Sanskrit root  कृ, meaning 'to do, make, perform, accomplish, cause, effect, prepare, undertake'. Karma is related to the verbal Proto-Indo-European root kwer- 'to make, form'.

The root  is common in ancient Sanskrit literature, and it is relied upon to explain ideas in Rigveda, other Vedas, Upanishads, Puranas, and the Epics of Hinduism.

Practices
The Yoga Sutras of Patanjali 2.1 defines three types of, namely tapas (ascetic devotion), svadhyaya (study of the self or the scriptures), and (devotion or surrender to higher consciousness).

The yogic purifications or shatkarmas are sometimes called the Shatkriyas ("the six actions").

The Kriya Yoga school, established by Yogananda, is centered on pranayama techniques.