Saṅkhāra
(Pali; सङ्खार; Sanskrit: संस्कार or ) is a term figuring prominently in Buddhism. The word means 'formations' or 'that which has been put together' and 'that which puts together'. In the first (passive) sense,  refers to conditioned phenomena generally but specifically to all mental "dispositions". These are called 'volitional formations' both because they are formed as a result of volition and because they are causes for the arising of future volitional actions. English translations for  in the first sense of the word include 'conditioned things,' 'determinations,' 'fabrications' and 'formations' (or, particularly when referring to mental processes, 'volitional formations'). In the second (active) sense of the word,  refers to karma (sankhara-khandha) that leads to conditioned arising, dependent origination. According to the Vijnanavada school, there are 51 samskaras or mental factors. Etymology and meaning
Saṅkhāra is a Pali word that is cognate with the Sanskrit word saṃskāra. The latter word is not a Vedic Sanskrit term, but found extensively in classical and epic era Sanskrit in all Indian philosophies. Saṃskāra is found in the Hindu Upanishads such as in verse 2.6 of Kaushitaki Upanishad, 4.16.2–4 of Chandogya Upanishad, 6.3.1 of Brihadaranyaka Upanishad as well as mentioned by the ancient Indian scholar Panini and many others. Saṅkhāra appears in the Buddhist Pitaka texts with a variety of meanings and contexts, somewhat different from the Upanishadic texts, particularly for anything to predicate impermanence. It is a complex concept, with no single-word English translation, that fuses "object and subject" as interdependent parts of each human's consciousness and epistemological process. It connotes "impression, disposition, conditioning, forming, perfecting in one's mind, influencing one's sensory and conceptual faculty" as well as any "preparation, sacrament" that "impresses, disposes, influences or conditions" how one thinks, conceives or feels. Conditioned things
In the first (passive) sense,  refers to "conditioned things" or "dispositions, mental imprint". All aggregates in the world – physical or mental concomitants, and all phenomena, state early Buddhist texts, are conditioned things. It can refer to any compound form in the universe whether a tree, a cloud, a human being, a thought or a molecule. All these are , as well as everything that is physical and visible in the phenomenal world are conditioned things, or aggregate of mental conditions. The Buddha taught that all saṅkhāras are impermanent and essenceless. These subjective dispositions, states David Kalupahana, "prevented the Buddha from attempting to formulate an ultimately objective view of the world". Since conditioned things and dispositions are perceptions and do not have real essence, they are not reliable sources of pleasure and they are impermanent. Understanding the significance of this reality is wisdom. This "conditioned things" sense of the word Saṅkhāra appears in Four Noble Truths and in Buddhist theory of dependent origination, that is how ignorance or misconceptions about impermanence and non-self leads to Taṇhā and rebirths. The Samyutta Nikaya II.12.1 presents one such explanation, as do other Pali texts. The last words of the Buddha, according to the Mahāparinibbāna Sutta, were "Disciples, this I declare to you: All conditioned things are subject to disintegration – strive on untiringly for your liberation." (Pali: ""). Sankhara-khandha

In the second (active) sense,  (or ) refers to the form-creating faculty of mind. It is part of the doctrine of conditioned arising or dependent origination (). In this sense, the term Sankhara is karmically active volition or intention, which generates rebirth and influences the realm of rebirth. Sankhara herein is synonymous with karma, and includes actions of the body, speech and mind. The  states that living beings are reborn (bhava, become) by means of actions of body and speech (kamma). The Buddha stated that all volitional constructs are conditioned by ignorance (avijja) of impermanence and non-self. It is this ignorance that leads to the origination of the sankharas and ultimately causes human suffering (dukkha). The cessation of all such sankharas () is synonymous with Awakening (bodhi), the attainment of nirvana. The end of conditioned arising or dependent origination in the karmic sense (Sankharas), yields the unconditioned phenomenon of nirvana. As the ignorance conditions the volitional formations, these formations condition,  in turn, the consciousness (viññāna). The Buddha elaborated:

'What one intends, what one arranges, and what one obsesses about: This is a support for the stationing of consciousness. There being a support, there is a landing [or: an establishing] of consciousness. When that consciousness lands and grows, there is the production of renewed becoming in the future. When there is the production of renewed becoming in the future, there is future birth, aging & death, sorrow, lamentation, pain, distress, & despair. Such is the origination of this entire mass of suffering & stress.' Mental factors

Mental factors (Sanskrit: caitasika; Pali: cetasika; Tibetan Wylie: sems byung) are formations (Sanskrit: saṅkhāra) concurrent with mind (Sanskrit: citta). They can be described as aspects of the mind that apprehend the quality of an object, and that have the ability to color the mind. Nibbana
The Buddha emphasized the need to purify dispositions rather than eliminate them completely. Kalupahana states that "the elimination of dispositions is epistemological suicide," as dispositions determine our perspectives. The development of one's personality in the direction of perfection or imperfection rests with one's dispositions. When preliminary nibbana with substrate occurs (that is, nibbana of a living being), constructive consciousness, that is, the house-builder, is completely destroyed and no new formations will be constructed. However, sankharas in the sense of constructed consciousness, which exists as a 'karmically-resultant-consciousness' (vipāka viññāna), continue to exist. Each liberated individual produces no new karma, but preserves a particular individual personality which is the result of the traces of his or her karmic heritage. The very fact that there is a psycho-physical substrate during the remainder of an arahant's lifetime shows the continuing effect of karma. English translations for the term Sankhara
 Activities (Ajahn Sucitto)
 Concoctions (Santikaro)
 Conditions
 Conditioning Factors
 Conditioned things
 Determinations
 Fabrications
 Formations (Bhikkhu Bodhi)
 Karmic formations
 Mental constructions
 Mental constructs (Bhante S. Dhammika)
 Preparations (Bhikkhu Katukurunde Ñāṇānanda) 
 Volitional activities
 Volitional dispositions
 Volitional formations (Bhikkhu Bodhi)

