Buddhism is a religion and philosophy focusing on the teachings of the Buddha Śākyamuni (Siddhārtha Gautama), who probably lived in the 5th century BCE. Buddhism spread throughout the ancient Indian sub-continent in the five centuries following the Buddha's death, and propagated into Central, Southeast, and East Asia over the next two millennia. Today, Buddhism is divided primarily into three traditions: Theravāda (Sanskrit: Sthaviravāda), Mahāyāna, and Vajrayāna. Buddhism continues to attract followers worldwide, and, with around 350 million followers, it is considered a major world religion.

A Buddha is considered to be a person who discovers the true nature of reality through years of study, investigation of the various religious practices of his time, and meditation. This transformational discovery is called bodhi or "enlightenment". Any person who has become awakened from the "sleep of ignorance" by directly realizing the true nature of reality is called a Buddha. Śākyamuni is said to have been only the latest of many of these; there were other Buddhas before him and there will be others in the future. According to the Buddha, any person can follow his example and become enlightened through the study of his words "Dharma" and putting them into practice, by leading a virtuous, moral life, and purifying his mind. In general, the aim of Buddhist practice is to end all kinds of suffering in life. To achieve this state, adherents seek to purify and train the mind by following the Noble Eightfold Path, or the Middle Way, and eventually to gain true knowledge of reality and thus attain liberation: nirodha or nirvāa (Pāli nibbāna).