Buddhism is a religion based on the teachings of Siddhārth Gautam Buddh, who lived between 566 and 486 BCE. Originating in India, Buddhism gradually spread throughout Asia to Central Asia, Sri Lanka, Tibet, Southeast Asia, as well as the East Asian countries of China, Mongolia, Korea, Japan, Vietnam, Nepal, Cambodia and Laos. With over 375 million followers, Buddhism is a major world religion.

The aim of Buddhist practice is to end the suffering of cyclic existence, samsara (Pali, Sanskrit), by awakening the practitioner to the realization of true reality, the achievement of liberation nirvana and Buddhahood. To achieve this, one should act according to the laws of Karma: perform positive wholesome actions, avoid negative harmful actions, and purify and train the mind. Buddhist morality is underpinned by the principles of harmlessness and moderation. Mental training focuses on moral discipline (sila), meditative concentration (samadhi), and wisdom (prajñā).

Buddh, (known as Buddha in the western world), is a word in ancient Indian languages including Pāli and Sanskrit which means "one who has awakened". It is derived from the verbal root "budh", meaning "to awaken" or "to be enlightened". The word "Buddha" denotes not just Siddhartha Gautama, but a type of person, of which there have been infinite ones throughout the course of cosmic time. The historical Buddha is simply one member in the spiritual lineage of Buddhas. A Buddha is anyone who has fully awakened to the true nature of existence, liberated from the cycle of birth, death and rebirth, has eradicated all negative qualities and developed all positive qualities, including omniscience. The principles by which a person can achieve enlightenment are known as the Buddhadharma, or simply the Dharma, meaning (in this context) "law, doctrine, or truth".

Legend has it that Buddha was born around the 6th century BCE. His birthplace is said to be Lumbini in the Shākya state, one of a small group of old Hindu oligarchic republics. His father was a (Hindu) king, and Siddhārtha lived in luxury, being spared all hardship.

A a seer predicted shortly after his birth that Siddhartha would become either a great king or a great holy man; because of this, the king tried to make sure that Siddhartha never had any cause for dissatisfaction with his life, as that might drive him toward a spiritual path. Nevertheless, at the age of 29, he came across four sights; an old crippled man, a sick man, a decaying corpse, and finally a wandering holy man. These four sights led him to the realization that birth, old age, sickness and death come to everyone, not only once but repeated for life after life in succession since beginningless time. He decided to abandon his worldly life, leaving behind his wife, child and rank, etc. to take up the life of a wandering holy man in search of the answer to the problem of birth, old age, sickness, and death.

Indian holy men (sādhus) often engaged in a variety of ascetic practices designed to "mortify" the flesh. It was thought that by enduring pain and suffering, the ātman or "soul" became free from the cycle of rebirth. Siddhārtha proved adept at these practices, and was able to surpass his teachers. He and a small group of companions set out to take their austerities even further. After nearly starving himself to death with no success, Siddhārtha began to reconsider his path. Taking a little buttermilk from a passing goatherd, he found a large tree (now called the Bodhi tree) and set to meditating. He developed a new way of meditating, which began to bear fruit. His mind became concentrated and pure, and then, six years after he began his quest, he attained Enlightenment, and became a Buddha.

It is said that after his enlightenment, the Buddha was wondering whether or not he should teach the Dharma. He was concerned that, as human beings were overpowered by greed, hatred and delusion, they wouldn't be able to see the true Dharma which was subtle, deep and hard to understand. A god, Brahma Sahampati, however, interceded, and asked that he teach the Dharma to the world, as "There will be those who will understand the Dharma". With his great compassion, the Buddha agreed to become a teacher. At the Deer Park near Benares in northern India he delivered his first sermon to the group of five companions with whom he sought for enlightenment before. They, together with Buddha, formed the first sangha, the company of Buddhist monks.

It has also been advanced that the influence of Jain culture and philosophy in ancient Bihar gave rise to Buddhism. Buddhist scriptures describe various penances (tapas) undertaken by Gautama Siddhartha which appear identical to Jain penances. Buddhist writings reflect that Jainism was an already established faith -- rather than a newly founded or reformist one -- by the time Buddha lived. The Majjhima Nikaya relates instances of Buddha seeking converts from the apparently sizeable Nigantha (Jain) community. Both philosophies continue to share similar Prakrit terminology for important themes and teachings.

Principles of Buddhism

Buddhists seek refuge in what are often referred to as the Three Jewels. These are the Buddha, the Dharma (or Dhamma), and the "Arya" (noble) Sangha or community of monks and nuns. While it is impossible to escape one's Karma or the effects caused by previous thoughts, words and deeds, it is possible to avoid the suffering that comes from it by becoming enlightened. In this way, dharma offers a refuge. Many Buddhists take the refuges each day, often more than once in order to remind themselves of what they are doing and to direct their resolve inwardly towards liberation. In all forms of Buddhism, refuge in the Three Jewels are taken before the Sangha for the first time, as a part of the conversion ritual. The main goal of Buddhism is to escape from the suffering of cyclic existence.

The Four Noble Truths: The Buddha taught that life was dissatisfactory because of craving, but that this condition was curable by following the Eightfold Path. This teaching is called the Four Noble Truths:

Dukkha: All worldly life is unsatisfactory, disjointed, containing suffering.
Samudaya: There is a cause of suffering, which is attachment or desire (tanha) rooted in ignorance.
Nirodha: There is an end of suffering, which is Nirvana.
Marga: There is a path that leads out of suffering, known as the Noble Eightfold Path.

Noble Eightfold Path: In order to fully understand the noble truths and investigate whether they were in fact true, Buddha recommended that a certain lifestyle or path be followed which consists of:

Right Understanding
Right Thought
Right Speech
Right Action
Right Livelihood
Right Effort
Right Mindfulness
Right Concentration
 
The Eightfold Path essentially consists of meditation, following the precepts, and cultivating the positive converse of the precepts (e.g. benefiting living beings is the converse of the first precept of harmlessness). The Path may also be thought of as a way of developing śīla, meaning mental and moral discipline.

The Five Precepts: Buddhists undertake certain precepts as aids on the path to coming into contact with ultimate reality. Laypeople generally undertake five precepts. These are: 

To refrain from harming living creatures (killing).
To refrain from taking that which is not freely given (stealing).
To refrain from sexual misconduct.
To refrain from incorrect speech (lying, harsh language, slander, idle chit-chat).
To refrain from intoxicants which lead to loss of mindfulness.

One of the distinguishing features of the Buddhist precepts is that they are wider-ranging in implication than the "commandments" of some other religions. The first precept, against killing, for example, forbids the killing of animals as well as humans. In some schools of Buddhism, serious lay people or aspiring monks take an additional three to five ethical precepts, and some of the five precepts are strengthened. Fully ordained monks and nuns of the Theravada school also vow to follow the 227 patimokkha rules. Fully ordained Mahayana monks and nuns follow 348 equivalent rules with an additional set of, generally, 41 bodhisattva vows.

According to the Buddhist tradition, all phenomena (dharmas) are marked by three characteristics, sometimes referred to as the Dharma Seals:

Anatta: In Indian philosophy, the concept of a self is called ātman (that is, "soul" or metaphysical self), which refers to an unchanging, permanent essence conceived by virtue of existence. This concept and the related concept of Brahman, the Vedantic monistic ideal, which was regarded as an ultimate ātman for all beings, were indispensable for mainstream Indian metaphysics, logic, and science. The Buddha however emphasized changeability and not permanence. He taught that all concepts of a substantial personal self were incorrect, and formed in the realm of ignorance. But in a number of Mahayana sutras, the Buddha is presented as saying that, while the skandhas (constituents of the ordinary body and mind) are not the Self, there does truly exist an eternal, unchanging, blissful Buddha-essence in all sentient beings, which is the uncreated and deathless Buddha-nature ("Buddha-dhatu") or "True Self" of the Buddha himself. This immaculate Buddhic Self (Atman) is in no way to be construed as a mundane, impermanent, suffering "ego", of which it is the diametrical opposite.
 
The Nikāyas and Āgamas scriptures are ambivalent with regard to the Buddha's views on the existence or otherwise of a permanent self (ātman / atta). Though he is clearly reported to have criticized many of the heterodox concepts concerning an eternal personal self and to have denied the existence of an eternal self with regards to any of the constituent elements (skandha) of a being, nevertheless he is not reported to have explictly denied the existence of a non-personal, permanent self, contrary to the popular, orthodox view of the Buddha's teachings. Moreover, when the Buddha predicates "anātman" (anatta) with regards to the constituents of a being, there is a grammatical ambivalence in the use of the term.

Anicca: All compounded phenomena (things and experiences) are inconstant, unsteady, and impermanent. (Practically) everything is made up of parts, and is dependent on the right conditions for its existence. 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. Nothing lasts.

Dukkha: Because we fail to truly grasp the first two conditions, we suffer. We desire lasting satisfaction and happiness, but look for it amongst constantly changing phenomena. We perceive a self, and act to enhance that self by pursuing pleasure, and seek to prolong pleasure when the self too is a fleeting phenomenon.

Buddha-dhatu ("Buddha-Principle", Buddha-nature)
The Buddha's Mahayana doctrines contain a set of "ultimate" (nitartha) teachings on the immanence of a hidden core Reality within all sentient beings which is linked to the eternality of the Buddha and Nirvana. This immanent yet transcendent essence is variously called, in the key tathagatagarbha sutras which expound it, the Buddha-dhatu ("Buddha-element", Buddha-nature) or the Tathagatagarbha. This Buddha-dhatu is empty of all that is contingent, painful and impermanent. In the Nirvana Sutra, it is called by the Buddha the "True Self" (to distinguish it from the "false" worldly self of the five skandhas).

Other principles and practices

Meditation or dhyāna of some form is a common practice in most if not all schools of Buddhism, for the clergy if not the laity. Central to Buddhist doctrine and practice is the law of karma and vipaka; action and its fruition, which happens within the dynamic of dependent origination (pratītya-samutpāda). Actions which result in positive retribution (happiness) are defined as skillful or good, while actions that produce negative results (suffering) are called unskillful actions. These actions are expressed by the way of mind, body or speech. Some actions bring instant retribution while the results of other actions may not appear until a future lifetime.
 
Rebirth, which is closely related to the law of Karma. An action in this life may not give fruit or reaction until the next life time. This being said, action in a past life takes effect in this one, making a chain of existence. The full realization of the absence of an eternal self or soul breaks this cycle of birth and death (samsara).

The three main branches of Buddhism

Buddhism has evolved into myriad schools that can be roughly grouped into three types: Nikaya (also called Hinayana), Mahayana, and Vajrayana. Of the Nikaya schools, only the Theravada survives. Each branch sees itself as representing the true, original teachings of the Buddha, and some schools believe that the dialectic nature of Buddhism allows its format, terminology, and techniques to adapt over time in response to changing circumstances, thus validating dharmic approaches different from their own.

Although Buddhists concur that taking refuge should be undertaken with proper motivation and an understanding of the objects of refuge, the Indian scholar Atisha identified that in practice there are many different motives found for taking refuge. His idea was to use these different motivations as a key to resolving any apparent conflicts between all the Buddha's teachings without depending upon some form of syncretism that would cause as much confusion as it attempted to alleviate. The various motives for taking refuge are enumerated as follows, typically introduced using the concept of the "scope" (level of motivation) of a practitioner:

Worldly scope: to improve the lot of this life - this is not a Buddhist motivation.
Low scope: to gain high rebirth and avoid the low realms.
Middle scope: to achieve Nirvana (liberation from rebirth).
High scope: to achieve Buddhahood in order to liberate others from suffering, the basis of the Mahayana path.
Highest scope is also sometimes included: to achieve Buddhahood as soon as possible - in this life - which is the scope of the highest teachings on the Vajrayana (tantric) path.

The Theravada school, whose name means "Doctrine of the Elders", bases its practice and doctrine exclusively on the Pali Canon, which is a collection of what are known as agamas or nikaya sutras. The nikaya sutras are generally considered by modern scholars to be the oldest of the surviving types of Buddhist literature, and they are accepted as authentic in every branch of Buddhism. Theravada is the only surviving representative of the historical Nikaya branch. Nikaya Buddhism and consequently Theravada are sometimes referred to as Hinayana or "small vehicle", although this is considered by some to be impolite. Native Theravada is practiced today in Sri Lanka, Burma, Laos, Thailand, Cambodia and portions of China, Vietnam, and Malaysia. The aim of Nikaya Buddhism is to achieve liberation from rebirth and thus Nirvana.

The Mahāyāna branch emphasizes universal compassion and the selfless ideal of the bodhisattva, whose goal is to achieve Buddhahood in order to be of greatest benefit to other sentient beings. In addition to the Nikaya scriptures, Mahāyāna schools recognize all or part of a genre of scriptures that were first put in writing around 1 CE. These scriptures were written in some form of Sanskrit, except a few manuscripts in Prakrit, and are concerned with the purpose of achieving Buddhahood by following the path of the bodhisattva over the course of what is often described as countless eons of time. Because of this immense timeframe, some Mahāyāna schools accept the idea of working towards rebirth in a Pure Land. The Pure Land is normally conceived of as a state which is not enlightenment in itself but which is a highly conducive environment for working toward enlightenment, although some sources indicate that it is synonymous with enlightenment. Native Mahāyāna Buddhism is practiced today in China, Japan, Korea, and most of Vietnam.

The Vajrayāna or "Diamond Vehicle" (also referred to as Mantrayana, Tantrayana, Tantric or esoteric Buddhism) shares the basic concepts of Mahāyāna, but also includes a vast array of spiritual techniques designed to enhance Buddhist practice. Vajrayana Buddhism exists today in the form of two major sub-schools: Tibetan Buddhism and Shingon Buddhism. One component of the Vajrayāna is harnessing psycho-physical energy as a means of developing profoundly powerful states of concentration and awareness. These profound states are in turn to be used as an efficient path to Buddhahood. In addition to the Theravada and Mahāyāna scriptures, Vajrayāna Buddhists recognise a large body of texts that include the Buddhist Tantras. Native Vajrayana is practiced today mainly in Tibet, Nepal, Bhutan, Mongolia, Kalmykia (in Russia), Siberia (in Russia), areas of India, and -- among the Shingon (Zhènyān, 真言) and Tendai schools -- in China and Japan.

Buddhism after the Buddha

Buddhism spread slowly in India until the powerful Mauryan emperor Asoka converted to it and actively supported it. His promotion led to construction of Buddhist religious sites and missionary efforts that spread the faith into the countries listed at the beginning of the article. After about 500 CE, Buddhism showed signs of waning in India, becoming nearly extinct after about 1200 CE. This was due to Hinduism's revival movements such as Advaita and the rise of the bhakti movement. Some areas of India never parted from Buddhism, including Ladakh and other areas bordering the Tibetan, Nepali and Bhutanese borders.

In China and Japan, it adopted aspects of the native beliefs of Confucianism, Taoism and Shinto respectively. In Tibet, the Tantric Vajrayana lineage was preserved after it disappeared in India.

It is said that Kanishka gathered 500 monks, headed by Vasumitra, primarily, it seems, to compile extensive commentaries on the Abhidharma. Scholars believe that it was also around this time that a significant change was made in the language of the Sarvāstivādin canon, by converting an earlier Prakrit version into Sanskrit. This event was of particular significance since Sanskrit was the learned language of scholars in India, regardless of their specific religious or philosophical allegiance, thus enabling a far wider audience to gain access to Buddhist ideas and practices. For this reason, all major Buddhist scholars in India thereafter wrote their commentaries and treatises in Sanskrit.

Around the 1st century, Buddhism spread from India through successive waves of merchants and pilgrims. It reached as far as Turkmenistan and Arabia to the west, and eastward to southeast Asia, where the first records of Buddhism date from around 400. Mahayana Buddhism established a major regional center in what is today Afghanistan, and from there it spread to China, Korea, Mongolia, Japan and Vietnam. In 475, the Indian monk Bodhidharma traveled to China and established the Chan (Chinese; Japanese: Zen), school. During the first millennium, monks from China made pilgrimages to India and wrote accounts of their travels when they returned home. These Chinese travel records constitute extremely valuable sources for information concerning the state of Buddhism in India during the early medieval period.

Vajrayana also evolved at this stage carried from India to Tibet from around 800 by teachers such as Padmasambhava and Atisha. There it initially coexisted with native belief systems such as Bön, but later came to largely supplant or absorb them. An early form of esoteric Vajrayana known as Shingon was also transmitted by the priest Kūkai to Japan, where it continues to be practiced.

There is an active debate as to whether or not Tantrism was initially developed within Buddhism or Hinduism. Buddhist literature tends to predate the later puranic Tantras, and there is some evidence to suggest that the basic structure of tantra depends upon the Mahayana Buddhist philosophical schools. However, it is thought by others that meditative Shiva sects seem to have existed from pre-Vedic times; also, from scriptural citations and study of the Vedas, some say Tantra saw its philosophical basis in the mystical rites and mantras of the Atharva Veda (and later the Hindu Upanishads and Mahayana school of Buddhism).

Scriptures
The Buddhist canon of scripture is known in Sanskrit as the Tripitaka and in Pāli as the Tipitaka. These terms literally mean "three baskets" and refers to the three main divisions of the canon, which are:

The Vināya Pitaka, containing disciplinary rules for the Sangha of Buddhist monks and nuns, as well as a range of other texts which explain why and how rules were instituted, supporting material, and doctrinal clarification. The Sutta Pitaka (Pāli; Sanskrit: Sutra Pitaka), containing discourses of the Buddha. The Abhidhamma (Skt: Abhidharma) or commentary Pitaka, containing a philosophical systematization of the Buddha's teaching, including a detailed analysis of Buddhist psychology. During the first few centuries after Gautama Buddha, his teachings were transmitted orally, but around the 1st Century CE they began to be written down. The most notable set of texts from the early period is the Pali Canon, which was preserved in Sri Lanka by the Theravāda school. The sutras it contains are also part of the canon of every other Buddhist sect.

Mahāyāna tradition brought with it a collection of new texts, composed in Buddhist Hybrid Sanskrit, many of which were also described as actual sermons of the Buddha. These include the Perfection of Wisdom Sutras, the Avataṃsaka, the Lotus Sutra, the Vimalakīrti Sutra, and the Nirvana Sutra.

A detailed compilation of Mahayana works is found in the Tibetan canon. This is split into those texts attributed to be authored by the Buddha (Kanjur), and those texts which are understood to be commentaries by Indian practitioners (Tenjur). Vajrayāna practitioners also study the Buddhist Tantras.