Buddhism is a nontheistic religion or philosophy (Sanskrit: dharma; Pali: dhamma), that encompasses a variety of traditions, beliefs and practices largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha ("the awakened one"). According to Buddhist tradition, the Buddha lived and taught in the eastern part of the Indian subcontinent sometime between the 6th and 4th centuries BCE. He is recognized by Buddhists as an awakened or enlightened teacher who shared his insights to help sentient beings end their suffering through the elimination of ignorance and craving. Buddhists believe that this is accomplished through direct understanding and the perception of dependent origination and the Four Noble Truths. The ultimate goal of Buddhism can either be Arhatship, Buddhahood or rainbow body depending on the branch of Buddhism.
Two major extant branches of Buddhism are generally recognized: Theravada ("The School of the Elders") and Mahayana ("The Great Vehicle"). Theravada has a widespread following in Sri Lanka and Southeast Asia (Cambodia, Laos, Thailand, Myanmar etc.). Mahayana is found throughout East Asia (China, Korea, Japan, Vietnam, Singapore, Taiwan etc.) and includes the traditions of Pure Land, Zen, Nichiren Buddhism, Tibetan Buddhism, Shingon, and Tiantai (Tendai). In some classifications Vajrayana, a body of teachings attributed to Indian siddhas, is recognized as a third branch while others classify it as a part of Mahayana.

Buddhist Concepts

Life and the World

Samsara
Within Buddhism, samsara is defined as the continual repetitive cycle of birth and death that arises from ordinary beings' grasping and fixating on a self and experiences. Specifically, samsara refers to the process of cycling through one rebirth after another within the six realms of existence, where each realm can be understood as physical realm or a psychological state characterized by a particular type of suffering. Samsara arises out of avidya (ignorance) and is characterized by dukkha (suffering, anxiety, dissatisfaction). In the Buddhist view, liberation from samsara is possible by following the Buddhist path.

Karma
In Buddhism, Karma (from Sanskrit: "action, work") is the force that drives saṃsāra—the cycle of suffering and rebirth for each being. Good, skillful deeds (Pāli: "kusala") and bad, unskillful (Pāli: "akusala") actions produce "seeds" in the mind that come to fruition either in this life or in a subsequent rebirth. The avoidance of unwholesome actions and the cultivation of positive actions is called śīla (from Sanskrit: "ethical conduct").
In Buddhism, karma specifically refers to those actions of body, speech or mind that spring from mental intent ("cetana"), and bring about a consequence or fruit, (phala) or result (vipāka).
In Theravada Buddhism there can be no divine salvation or forgiveness for one's karma, since it is a purely impersonal process that is a part of the makeup of the universe. In Mahayana Buddhism, the texts of certain Mahayana sutras (such as the Lotus Sutra, the Angulimaliya Sutra and the Nirvana Sutra) claim that the recitation or merely the hearing of their texts can expunge great swathes of negative karma. Some forms of Buddhism (for example, Vajrayana) regard the recitation of mantras as a means for cutting off of previous negative karma. The Japanese Pure Land teacher Genshin taught that Amida Buddha has the power to destroy the karma that would otherwise bind one in saṃsāra.

Rebirth
Rebirth refers to a process whereby beings go through a succession of lifetimes as one of many possible forms of sentient life, each running from conception to death. Buddhism rejects the concepts of a permanent self or an unchanging, eternal soul, as it is called in Hinduism and Christianity. According to Buddhism there ultimately is no such thing as a self independent from the rest of the universe (the doctrine of anatta). Buddhists also refer to themselves as the believers of the anatta doctrine—Nairatmyavadin or Anattavadin. Rebirth in subsequent existences must be understood as the continuation of a dynamic, ever-changing process of "dependent arising" ("pratītyasamutpāda") determined by the laws of cause and effect (karma) rather than that of one being, transmigrating or incarnating from one existence to the next.
Each rebirth takes place within one of five realms according to Theravadins, or six according to other schools.
    Naraka beings: those who live in one of many Narakas (Hells);
    Preta: sometimes sharing some space with humans, but invisible to most people; an important variety is the hungry ghost;
    Animals: sharing space with humans, but considered another type of life;
    Human beings: one of the realms of rebirth in which attaining Nirvana is possible;
    Asuras: variously translated as lowly deities, demons, titans, antigods; not recognized by Theravāda (Mahavihara) tradition as a separate realm;
    Devas including Brahmas: variously translated as gods, deities, spirits, angels, or left untranslated.
 

Suffering's Causes and Solution

The Four Noble Truths
The teachings on the Four Noble Truths are regarded as central to the teachings of Buddhism, and are said to provide a conceptual framework for Buddhist thought. These four truths explain the nature of dukkha (suffering, anxiety, unsatisfactoriness), its causes, and how it can be overcome. The four truths are:
    The truth of dukkha (suffering, anxiety, unsatisfactoriness)
    The truth of the origin of dukkha
    The truth of the cessation of dukkha
    The truth of the path leading to the cessation of dukkha
 

Noble Eightfold Path
The Noble Eightfold Path—the fourth of the Buddha's Noble Truths—consists of a set of eight interconnected factors or conditions, that when developed together, lead to the cessation of dukkha. These eight factors are: Right View (or Right Understanding), Right Intention (or Right Thought), Right Speech, Right Action, Right Livelihood, Right Effort, Right Mindfulness, and Right Concentration.
Ajahn Sucitto describes the path as "a mandala of interconnected factors that support and moderate each other." The eight factors of the path are not to be understood as stages, in which each stage is completed before moving on to the next. Rather, they are understood as eight significant dimensions of one's behaviour—mental, spoken, and bodily—that operate in dependence on one another; taken together, they define a complete path, or way of living.

The Four Immeasurables
While he searched for enlightenment, Gautama combined the yoga practice of his teacher Kalama with what later became known as "the immeasurables". Gautama thus invented a new kind of human, one without egotism. What Thich Nhat Hanh calls the "Four Immeasurable Minds" of love, compassion, joy, and equanimity are also known as brahmaviharas, divine abodes, or simply as four immeasurables. Pema Chödrön calls them the "four limitless ones". Of the four, mettā or loving-kindness meditation is perhaps the best known. The Four Immeasurables are taught as a form of meditation that cultivates "wholesome attitudes towards all sentient beings."
The practitioner prays:
    May all sentient beings have happiness and its causes,
    May all sentient beings be free of suffering and its causes,
    May all sentient beings never be separated from bliss without suffering,
    May all sentient beings be in equanimity, free of bias, attachment and anger.

Middle Way
An important guiding principle of Buddhist practice is the Middle Way (or Middle Path), which is said to have been discovered by Gautama Buddha prior to his enlightenment. The Middle Way has several definitions:
    The practice of non-extremism: a path of moderation away from the extremes of self-indulgence and self-mortification;
    The middle ground between certain metaphysical views (for example, that things ultimately either do or do not exist);
    An explanation of Nirvana (perfect enlightenment), a state wherein it becomes clear that all dualities apparent in the world are delusory;
    Another term for emptiness, the ultimate nature of all phenomena (in the Mahayana branch), a lack of inherent existence, which avoids the extremes of permanence and nihilism or inherent existence and nothingness.

Nature of Existence
Buddhist scholars have produced a number of intellectual theories, philosophies and world view concepts (see, for example, Abhidharma, Buddhist philosophy and Reality in Buddhism). Some schools of Buddhism discourage doctrinal study, and some regard it as essential practice.
The concept of liberation (nirvāṇa)—the goal of the Buddhist path—is closely related to overcoming ignorance (avidyā), a fundamental misunderstanding or mis-perception of the nature of reality. In awakening to the true nature of the self and all phenomena one develops dispassion for the objects of clinging, and is liberated from suffering (dukkha) and the cycle of incessant rebirths (saṃsāra). To this end, the Buddha recommended viewing things as characterized by the three marks of existence.

Three Marks of Existence
Impermanence (Pāli: anicca) expresses the Buddhist notion that all compounded or conditioned phenomena (all things and experiences) are inconstant, unsteady, and impermanent. Everything we can experience through our senses is made up of parts, and its existence is dependent on external conditions. Everything is in constant flux, and so conditions and the thing itself are constantly changing. Things are constantly coming into being, and ceasing to be. Since nothing lasts, there is no inherent or fixed nature to any object or experience. According to the doctrine of impermanence, life embodies this flux in the aging process, the cycle of rebirth (saṃsāra), and in any experience of loss. The doctrine asserts that because things are impermanent, attachment to them is futile and leads to suffering (dukkha).
Suffering (Pāli: दुक्ख dukkha; Sanskrit दुःख duḥkha) is also a central concept in Buddhism. The word roughly corresponds to a number of terms in English including suffering, pain, unsatisfactoriness, sorrow, affliction, anxiety, dissatisfaction, discomfort, anguish, stress, misery, and frustration. Although the term is often translated as "suffering", its philosophical meaning is more analogous to "disquietude" as in the condition of being disturbed. As such, "suffering" is too narrow a translation with "negative emotional connotations" that can give the impression that the Buddhist view is pessimistic, but Buddhism seeks to be neither pessimistic nor optimistic, but realistic. In English-language Buddhist literature translated from Pāli, "dukkha" is often left untranslated, so as to encompass its full range of meaning.
Not-self (Pāli: anatta; Sanskrit: anātman) is the third mark of existence. Upon careful examination, one finds that no phenomenon is really "I" or "mine"; these concepts are in fact constructed by the mind. In the Nikayas anatta is not meant as a metaphysical assertion, but as an approach for gaining release from suffering. In fact, the Buddha rejected both of the metaphysical assertions "I have a Self" and "I have no Self" as ontological views that bind one to suffering. When asked if the self was identical with the body, the Buddha refused to answer. By analyzing the constantly changing physical and mental constituents (skandhas) of a person or object, the practitioner comes to the conclusion that neither the respective parts nor the person as a whole comprise a self.

Dependent Arising
The doctrine of pratītyasamutpāda, (Sanskrit; Pali: paticcasamuppāda; Tibetan: rten.cing.'brel.bar.'byung.ba; Chinese: 緣起) is an important part of Buddhist metaphysics. It states that phenomena arise together in a mutually interdependent web of cause and effect. It is variously rendered into English as "dependent origination", "conditioned genesis", "dependent co-arising", "interdependent arising", or "contingency".

The best-known application of the concept of pratītyasamutpāda is the scheme of Twelve Nidānas (from Pāli "nidāna" meaning "cause, foundation, source or origin"), which explain the continuation of the cycle of suffering and rebirth (saṃsāra) in detail.

The Twelve Nidānas describe a causal connection between the subsequent characteristics or conditions of cyclic existence, each one giving rise to the next:

1.     Avidyā: ignorance, specifically spiritual ignorance of the nature of reality;
2.     Saṃskāras: literally formations, explained as referring to karma;
3.     Vijñāna: consciousness, specifically discriminative;
4.     Nāmarūpa: literally name and form, referring to mind and body;
5.     Ṣaḍāyatana: the six sense bases: eye, ear, nose, tongue, body and mind-organ;
6.     Sparśa: variously translated contact, impression, stimulation (by a sense object);
7.     Vedanā: usually translated feeling: this is the "hedonic tone", i.e. whether something is pleasant, unpleasant or neutral;
8.     Tṛṣṇā: literally thirst, but in Buddhism nearly always used to mean craving;
9.     Upādāna: clinging or grasping; the word also means fuel, which feeds the continuing cycle of rebirth;
10.     Bhava: literally being (existence) or becoming. (The Theravada explains this as having two meanings: karma, which produces a new existence, and the existence itself.);
11.     Jāti: literally birth, but life is understood as starting at conception;
12.     Jarāmaraṇa: (old age and death) and also soka, parideva, dukkha, domanassa and upāyāsā (sorrow, lamentation, pain, affliction and despair).

Emptiness
Mahayana Buddhism received significant theoretical grounding from Nagarjuna (perhaps c. 150–250 CE), arguably the most influential scholar within the Mahayana tradition. Nagarjuna's primary contribution to Buddhist philosophy was the systematic exposition of the concept of śūnyatā, or "emptiness", widely attested in the Prajñāpāramitā sutras that emerged in his era. The concept of emptiness brings together other key Buddhist doctrines, particularly anatta and dependent origination, to refute the metaphysics of Sarvastivada and Sautrantika (extinct non-Mahayana schools). For Nagarjuna, it is not merely sentient beings that are empty of ātman; all phenomena (dharmas) are without any svabhava (literally "own-nature" or "self-nature"), and thus without any underlying essence; they are "empty" of being independent; thus the heterodox theories of svabhava circulating at the time were refuted on the basis of the doctrines of early Buddhism. Nagarjuna's school of thought is known as the Mādhyamaka. Some of the writings attributed to Nagarjuna made explicit references to Mahayana texts, but his philosophy was argued within the parameters set out by the agamas. He may have arrived at his positions from a desire to achieve a consistent exegesis of the Buddha's doctrine as recorded in the Canon. In the eyes of Nagarjuna the Buddha was not merely a forerunner, but the very founder of the Mādhyamaka system.

Liberation
 

Nirvana
Nirvana (Sanskrit; Pali: "Nibbana") means "cessation", "extinction" (of craving and ignorance and therefore suffering and the cycle of involuntary rebirths (saṃsāra)), "extinguished", "quieted", "calmed"; it is also known as "Awakening" or "Enlightenment" in the West. The term for anybody who has achieved nirvana, including the Buddha, is arahant.
Bodhi (Pāli and Sanskrit, in devanagari: बॊधि) is a term applied to the experience of Awakening of arahants. Bodhi literally means "awakening", but it is more commonly translated into English as "enlightenment". In Early Buddhism, bodhi carried a meaning synonymous to nirvana, using only some different metaphors to describe the experience, which implies the extinction of raga (greed, craving), dosa (hate, aversion) and moha (delusion). In the later school of Mahayana Buddhism, the status of nirvana was downgraded in some scriptures, coming to refer only to the extinction of greed and hate, implying that delusion was still present in one who attained nirvana, and that one needed to attain bodhi to eradicate delusion.

Buddhas
According to Buddhist traditions a Buddha is a fully awakened being who has completely purified his mind of the three poisons of desire, aversion and ignorance. A Buddha is no longer bound by Samsara and has ended the suffering which unawakened people experience in life.
Buddhists do not consider Siddhartha Gautama to have been the only Buddha. The Pali Canon refers to many previous ones (see List of the 28 Buddhas), while the Mahayana tradition additionally has many Buddhas of celestial, rather than historical, origin (see Amitabha or Vairocana as examples, for lists of many thousands Buddha names see Taishō Shinshū Daizōkyō numbers 439–448). A common Theravada and Mahayana Buddhist belief is that the next Buddha will be one named Maitreya (Pali: Metteyya).

According to Theravada
In Theravada doctrine, a person may awaken from the "sleep of ignorance" by directly realizing the true nature of reality; such people are called arahants and occasionally buddhas. After numerous lifetimes of spiritual striving, they have reached the end of the cycle of rebirth, no longer reincarnating as human, animal, ghost, or other being. The commentaries to the Pali Canon classify these awakened beings into three types:

•     Sammasambuddha, usually just called the Buddha, who discovers the truth by himself and teaches the path to awakening to others
•     Paccekabuddha, who discovers the truth by himself but lacks the skill to teach others
•     Savakabuddha, who receive the truth directly or indirectly from a Sammasambuddha

According to Mahayana
In the Mahayana, the Buddha tends not to be viewed as merely human, but as the earthly projection of a beginningless and endless, omnipresent being (see Dharmakaya) beyond the range and reach of thought. Moreover, in certain Mahayana sutras, the Buddha, Dharma and Sangha are viewed essentially as One: all three are seen as the eternal Buddha himself.
The Buddha's death is seen as an illusion, he is living on in other planes of existence, and monks are therefore permitted to offer "new truths" based on his input. Mahayana also differs from Theravada in its concept of śūnyatā (that ultimately nothing has existence), and in its belief in bodhisattvas (enlightened people who vow to continue being reborn until all beings can be enlightened).

Buddha Eras
Buddhists believe Gautama Buddha was the first to achieve enlightenment in this Buddha era and is therefore credited with the establishment of Buddhism. A Buddha era is the stretch of history during which people remember and practice the teachings of the earliest known Buddha. This Buddha era will end when all the knowledge, evidence and teachings of Gautama Buddha have vanished. This belief therefore maintains that many Buddha eras have started and ended throughout the course of human existence. The Gautama Buddha, then, is the Buddha of this era, who taught directly or indirectly to all other Buddhas in it (see types of Buddhas).

Bodhisattvas
Bodhisattva means "enlightenment being", and generally refers to one who is on the path to buddhahood. Traditionally, a bodhisattva is anyone who, motivated by great compassion, has generated bodhicitta, which is a spontaneous wish to attain Buddhahood for the benefit of all sentient beings. Theravada Buddhism primarily uses the term in relation to Gautama Buddha's previous existences, but has traditionally acknowledged and respected the bodhisattva path as well.

Practice

Devotion
Devotion is an important part of the practice of most Buddhists. Devotional practices include bowing, offerings, pilgrimage, and chanting. In Pure Land Buddhism, devotion to the Buddha Amitabha is the main practice. In Nichiren Buddhism, devotion to the Lotus Sutra is the main practice.

Yoga
Buddhism traditionally incorporates states of meditative absorption (Pali: jhāna; Skt: dhyāna). The most ancient sustained expression of yogic ideas is found in the early sermons of the Buddha. One key innovative teaching of the Buddha was that meditative absorption must be combined with liberating cognition. The difference between the Buddha's teaching and the yoga presented in early Brahminic texts is striking. Meditative states alone are not an end, for according to the Buddha, even the highest meditative state is not liberating. Instead of attaining a complete cessation of thought, some sort of mental activity must take place: a liberating cognition, based on the practice of mindful awareness.

Refuge in the Three Jewels
Traditionally, the first step in most Buddhist schools requires taking refuge in the Three Jewels (Sanskrit: tri-ratna, Pāli: ti-ratana) as the foundation of one's religious practice. The practice of taking refuge on behalf of young or even unborn children is mentioned in the Majjhima Nikaya, recognized by most scholars as an early text (cf. Infant baptism). Tibetan Buddhism sometimes adds a fourth refuge, in the lama. In Mahayana, the person who chooses the bodhisattva path makes a vow or pledge, considered the ultimate expression of compassion. In Mahayana, too, the Three Jewels are perceived as possessed of an eternal and unchanging essence and as having an irreversible effect: "The Three Jewels have the quality of excellence. Just as real jewels never change their faculty and goodness, whether praised or reviled, so are the Three Jewels (Refuges), because they have an eternal and immutable essence. These Three Jewels bring a fruition that is changeless, for once one has reached Buddhahood, there is no possibility of falling back to suffering.
The Three Jewels are:

• The Buddha. This is a title for those who have attained Nirvana. See also the Tathāgata and Gautama Buddha. The Buddha could also be represented as a concept instead of a specific person: the perfect wisdom that understands Dharma and sees reality in its true form. In Mahayana Buddhism, the Buddha can be viewed as the supreme Refuge: "Buddha is the Unique Absolute Refuge. Buddha is the Imperishable, Eternal, Indestructible and Absolute Refuge."
• The Dharma. The teachings or law of nature as expounded by the Gautama Buddha. It can also, especially in Mahayana, connote the ultimate and sustaining Reality that is inseparable from the Buddha. Further, from some Mahayana perspectives, the Dharma embodied in the form of a great sutra (Buddhic scripture) can replace the need for a personal teacher and can be a direct and spontaneous gateway into Truth (Dharma). This is especially said to be the case with the Lotus Sutra. Hiroshi Kanno writes of this view of the Lotus Sutra: "it is a Dharma-gate of sudden enlightenment proper to the Great Vehicle; it is a Dharma-gate whereby one awakens spontaneously, without resorting to a teacher".
• The Sangha. Those who have attained any of the Four stages of enlightenment, or simply the congregation of monastic practitioners. The monks' order, which began during the lifetime of the Buddha, is among the oldest organizations on Earth.

Buddhist Ethics

Śīla (Sanskrit) or sīla (Pāli) is usually translated into English as "virtuous behavior", "morality", "ethics" or "precept". It is an action committed through the body, speech, or mind, and involves an intentional effort. It is one of the three practices (sila, samadhi, and panya) and the second pāramitā. It refers to moral purity of thought, word, and deed. The four conditions of śīla are chastity, calmness, quiet, and extinguishment.
Śīla is the foundation of Samadhi/Bhāvana (Meditative cultivation) or mind cultivation. Keeping the precepts promotes not only the peace of mind of the cultivator, which is internal, but also peace in the community, which is external. According to the Law of Karma, keeping the precepts are meritorious and it acts as causes that would bring about peaceful and happy effects. Keeping these precepts keeps the cultivator from rebirth in the four woeful realms of existence.
Śīla refers to overall principles of ethical behavior. There are several levels of sila, which correspond to "basic morality" (five precepts), "basic morality with asceticism" (eight precepts), "novice monkhood" (ten precepts) and "monkhood" (Vinaya or Patimokkha). Lay people generally undertake to live by the five precepts, which are common to all Buddhist schools. If they wish, they can choose to undertake the eight precepts, which add basic asceticism.

The five precepts are training rules in order to live a better life in which one is happy, without worries, and can meditate well:

1.     To refrain from taking life (non-violence towards sentient life forms), or ahimsā;
2.     To refrain from taking that which is not given (not committing theft);
3.     To refrain from sensual (including sexual) misconduct;
4.     To refrain from lying (speaking truth always);
5.     To refrain from intoxicants which lead to loss of mindfulness (specifically, drugs and alcohol).

The precepts are not formulated as imperatives, but as training rules that laypeople undertake voluntarily to facilitate practice. In Buddhist thought, the cultivation of dana and ethical conduct themselves refine consciousness to such a level that rebirth in one of the lower heavens is likely, even if there is no further Buddhist practice. There is nothing improper or un-Buddhist about limiting one's aims to this level of attainment.

In the eight precepts, the third precept on sexual misconduct is made more strict, and becomes a precept of celibacy. The three additional precepts are:

    6. To refrain from eating at the wrong time (eat only from sunrise to noon);
    7. To refrain from dancing and playing music, wearing jewelry and cosmetics, attending shows and other performances;
    8. To refrain from using high or luxurious seats and bedding.

The complete list of ten precepts may be observed by laypeople for short periods. For the complete list, the seventh precept is partitioned into two, and a tenth added:

    6. To refrain from taking food at an unseasonable time, that is after the mid-day meal;
    7. To refrain from dancing, music, singing and unseemly shows;
    8. To refrain from the use of garlands, perfumes, ointments, and from things that tend to beautify and adorn (the person);
    9. To refrain from (using) high and luxurious seats (and beds);
    10. To refrain from accepting gold and silver;

Monastic Life

Vinaya is the specific moral code for monks and nuns. It includes the Patimokkha, a set of 227 rules for monks in the Theravadin recension. The precise content of the vinayapitaka (scriptures on Vinaya) differs slightly according to different schools, and different schools or subschools set different standards for the degree of adherence to Vinaya. Novice-monks use the ten precepts, which are the basic precepts for monastics.

Meditation

Buddhist meditation is fundamentally concerned with two themes: transforming the mind and using it to explore itself and other phenomena. According to Theravada Buddhism the Buddha taught two types of meditation, samatha meditation (Sanskrit: śamatha) and vipassanā meditation (Sanskrit: vipaśyanā). In Chinese Buddhism, these exist (translated chih kuan), but Chán (Zen) meditation is more popular. According to Peter Harvey, whenever Buddhism has been healthy, not only monks, nuns, and married lamas, but also more committed lay people have practiced meditation. According to Routledge's Encyclopedia of Buddhism, in contrast, throughout most of Buddhist history before modern times, serious meditation by lay people has been unusual. The evidence of the early texts suggests that at the time of the Buddha, many male and female lay practitioners did practice meditation, some even to the point of proficiency in all eight jhānas (see the next section regarding these).

Samādhi (meditative cultivation): samatha meditation
In the language of the Noble Eightfold Path, samyaksamādhi is "right concentration". The primary means of cultivating samādhi is meditation. Upon development of samādhi, one's mind becomes purified of defilement, calm, tranquil, and luminous.
Once the meditator achieves a strong and powerful concentration (jhāna, Sanskrit ध्यान dhyāna), his mind is ready to penetrate and gain insight (vipassanā) into the ultimate nature of reality, eventually obtaining release from all suffering. The cultivation of mindfulness is essential to mental concentration, which is needed to achieve insight.

In Theravāda
In Theravāda Buddhism, the cause of human existence and suffering is identified as craving, which carries with it the various defilements. These various defilements are traditionally summed up as greed, hatred and delusion. These are believed deeply rooted afflictions of the mind that create suffering and stress. To be free from suffering and stress, these defilements must be permanently uprooted through internal investigation, analyzing, experiencing, and understanding of the true nature of those defilements by using jhāna, a technique of the Noble Eightfold Path. It then leads the meditator to realize the Four Noble Truths, Enlightenment and Nibbana. Nibbana is the ultimate goal of Theravadins.

Prajñā (Wisdom): vipassana meditation
Prajñā (Sanskrit) or paññā (Pāli) means wisdom that is based on a realization of dependent origination, The Four Noble Truths and the three marks of existence. Prajñā is the wisdom that is able to extinguish afflictions and bring about bodhi. It is spoken of as the principal means of attaining nirvāṇa, through its revelation of the true nature of all things as dukkha (unsatisfactoriness), anicca (impermanence) and anatta (not-self). Prajñā is also listed as the sixth of the six pāramitās of the Mahayana.

Zen
Zen Buddhism (禅), pronounced Chán in Chinese, seon in Korean or zen in Japanese (derived from the Sanskrit term dhyāna, meaning "meditation") is a form of Buddhism that became popular in China, Korea and Japan and that lays special emphasis on meditation. Zen places less emphasis on scriptures than some other forms of Buddhism and prefers to focus on direct spiritual breakthroughs to truth.

Vajrayana and Tantra
Though based upon Mahayana, Tibeto-Mongolian Buddhism is one of the schools that practice Vajrayana or "Diamond Vehicle" (also referred to as Mantrayāna, Tantrayāna, Tantric Buddhism, or esoteric Buddhism). It accepts all the basic concepts of Mahāyāna, but also includes a vast array of spiritual and physical techniques designed to enhance Buddhist practice. Tantric Buddhism is largely concerned with ritual and meditative practices. One component of the Vajrayāna is harnessing psycho-physical energy through ritual, visualization, physical exercises, and meditation as a means of developing the mind. Using these techniques, it is claimed that a practitioner can achieve Buddhahood in one lifetime, or even as little as three years. In the Tibetan tradition, these practices can include sexual yoga, though only for some very advanced practitioners.

Information Source: https://en.wikipedia.org

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Buddhism - Wikipedia, the free encyclopedia: Buddhism /ˈbudɪzəm/ is a nontheistic religion or philosophy (Sanskrit: dharma; Pali: dhamma), that encompasses a variety of traditions, beliefs and practices largely based on teachings attributed to Siddhartha Gautama, commonly known as the Buddha ("the awakened one").

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