Founded in the sixth century B.C. by the Indian Prince Siddhartha Gautama, Buddhism is one of the world's most widespread religions. As with all major religions, a great many historical schisms have split Buddhism into numerous sects. Most scholars divide Buddhism into three main branches, or yanas ("vehicles"). Early Buddhism, sometimes known as Hinayana Buddhism, is the religion's oldest sect, while the more accessible Mahayana and Vajrayana Buddhism are later forms of the religion that are adapted to various regions and cultures.

Early Buddhism

A pejorative term coined by the Mahayana Buddhists, "Hinayana" Buddhism is more respectfully known as "Early Buddhism." Early Buddhism is the religion's original sect, and its sole surviving school is known as Theravada Buddhism, practiced in much of Southeast Asia, including Thailand, Cambodia, Laos, Myanmar and Sri Lanka. The origins of Theravada Buddhism trace back to the very first followers of the Buddha himself, and its sacred texts are taken from an early Indian collection of the Buddha's teachings, written in the Pali language spoken in India during the time of Siddhartha Gautama, although which of these texts are considered scripture differs slightly by region. Theravada Buddhists hold sacred the four noble truths taught by the Buddha. This boils down to the idea that human suffering may be eliminated if we can successfully eliminate our own desires. The end goal within this sect is to attain nirvana, an escape from the cycle of death and rebirth to a state beyond desire and suffering. Those that follow the noble eightfold path and succeed in reaching nirvana are known in the Theravada school as arhats. According to Early Buddhist doctrine, the difficult task of reaching nirvana is only possible in this life for monks or ascetics.

Mahayana Buddhism

Mahayana Buddhism, the "Greater Vehicle," split from Early Buddhism in the first century and spread throughout much of East Asia. As opposed to Early Buddhists, Mahayana Buddhists believe that the path to nirvana should be open to all people rather than only monks. Rather than hoping to become arhats, Mahayana Buddhists hope to become bodhisattvas, enlightened saints who delay their own nirvana in order to help others. In addition to the Pali scripture used by the Theravada Buddhists, Mahayana Buddhists also accept later scriptures known as sutras, written in Sanskrit, and they believe in translating all the sacred texts into local languages. Mahayana Buddhists also revere many more buddhas and bodhisattvas than the Theravada Buddhists, and generally place more importance in ritual. Some of the major Mahayana sects are the Zen Buddhists, the Pure Land Buddhists and the Nichiren Buddhists, the teachings of the latter focusing even more heavily than the other Mahayana sects on the importance of the Lotus Sutra.

Vajrayana Buddhism

This branch of Buddhism, also known as Esoteric Buddhism, grew out of Mahayana Buddhism in India and is considered by many to be an extension of the Mahayana school. Its early texts were passed to China and then on to Japan, Korea, Tibet and Mongolia. Vajrayana Buddhists incorporated a range of ritual practices, often taken from other, older religions. The Japanese monk Kukai introduced this form of Buddhism to Japan, where it became known as Shingon Buddhism, one of the few remaining Vajrayana sects today. Another surviving group of Vajrayana Buddhists are the Newar Vajrayana Buddhists of Nepal's Kathmandu valley. As well as the various Indian Vajrayana deities, this group worships a few uniquely Newar deities.

Tibetan Buddhism

Perhaps the best-known form of Vajrayana Buddhism is found in Tibet. One of the last regions to do so, Tibet adopted Vajrayana Buddhism when it was introduced by the Indian mystic Padma Sambhava. As opposed to the Shingon and Newar Buddhists, Tibetan Buddhists center their focus on the newer texts of the Vajrayana, although there is some overlap in their sacred texts. Tibetan Buddhist teaching and rite also have certain elements of Theravada Buddhism and Bon, the older, shamanistic religion of Tibet. One set of scriptures that is unique to Tibetans contains a number of sexual rituals designed to help worshipers attain enlightenment. Tibetan Buddhism is further broken into four major divisions of its own: Nyingma Buddhism, the oldest Tibetan denomination, and the newer Kagyu, Sakya and Geluk sects of Buddhism.