Buddhism is a religion, a realistic philosophy, and arguably a psychology, focusing on the teachings of the Buddha Sakyamuni, who lived in antique India most likely from the mid-6th to the early 5th century BCE. Buddhism extend throughout the Indian subcontinent in the five centuries following the Buddha's passing, and propagated into Central, Southeast, and East Asia over the next two millennia. Today, Buddhism is divided primarily into three traditions: Theravada, Mahayana, and Vajrayana. Buddhism continues to magnetize followers worldwide, and, with about 708 million adherents, it is considered a major world religion. Buddhism is the fourth-largest religion in the world.
When used in a generic sense, a Buddha is usually considered to be a person who discovers the true nature of reality through years of spiritual cultivation, investigation of the variety of religious practices of his time, and meditation. This transformational discovery is called bodhi - literally, "Awakening”. Any person who has become awakened from the "sleep of ignorance" by directly realizing the true nature of reality is called a Buddha.