Today, Buddhism is divided primarily into three traditions:
Theravada (Sanskrit: स्थविरवाद Sthaviravāda);
Mahayana (Sanskrit: महायान Mahāyāna);
Vajrayana, which developed from, and is sometimes still classified with, Mahayana.
Theravada is still practiced in certain parts of South Asia (mostly Sri Lanka) and Southeast Asia; Mahayana is practiced predominantly in East Asia; and the esoteric Vajrayana is followed in Tibet and Mongolia. The earlier non-Theravada Hinayana schools of thought that stemmed from India largely died out a millennium ago.
Buddhism continues to attract followers worldwide and is considered a major world religion. According to one source (), "World estimates for Buddhists vary between 230 and 500 million, with most around 350 million." However, estimates are uncertain for several countries. Buddhism is the fifth-largest religion in the world behind Christianity, Islam, Hinduism, and traditional Chinese religion, respectively. The monks' order Sangha, which began during the lifetime of the Buddha in India, is amongst the oldest organizations on earth.
When used in a generic sense, a buddha is generally considered to be a person who discovers the true nature of reality through years of spiritual cultivation, investigation of the various religious practices of his time, and meditation. This transformational discovery is called bodhi (literally, "awakening" — more commonly called "enlightenment").
Any person who has awakened from the "sleep of ignorance" by directly realizing the true nature of reality is called a buddha. The Buddha 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 the mind.
The aim of Buddhist practice is to put an end to the sorrow (dukkha, Sanskrit/Pali: दुक्ख) of existence. In the words of the Buddha: "I teach one thing and one thing only: suffering and the end of suffering". To achieve this state of the end of suffering (Nirvana or Nirodha), adherents train and purify the mind by following the Four Noble Truths and the Noble Eightfold Path, eventually arriving at an understanding of the true nature of all things. In this way all ignorance and unhappiness ends, and liberation is attained.
Buddhist teaching encourages individuals to practice and verify the Buddha's teachings based on their own personal experience, and also after consulting with 'the wise'. If they find the teachings are valid (leading to more happiness and less suffering), they can apply these teachings in a practical form into their daily life if they so wish.