Three Vehicles of Buddhism
In order to clarify the variations between the many different schools and traditions of Buddhism in India, the schools are often divided into the three Yanas, meaning 'Vehicles' or 'Paths'. These three are: the Hinayana, Mahayana and Tantrayana.This can be understood as skilful means; a satisfying explanation to a learned philosopher is probably too complex for an uneducated person. On top of this, the Buddha clearly stated that he did not just intend to teach a doctrine, but intended to show the path that people can follow for their own development. This intention ultimately leads to the point where every individual has to decide which practices to follow and how to interpret the teachings, rather than adhering to a fixed doctrine.
THERAVADA AND HINAYANA: The Theravada being the first vehicle of buddhism is based on the set of teachings decided by the Third Council to contain the teachings of the Buddhism in India.SriLanka has played a central role in preserving the Theravada scriptures and practices. After the Third Council, the Tripitaka collection of sutras were taken to SriLanka. Most of these were originally in the Pali language, but some were compiled in other languages. Through the centuries however, all teachings were translated into Pali (around 35 BCE). Initially, most ordained Sangha were known as parivrajahas (wanderers). The teachings on the Four Noble Truths and meditation form the basis of Theravada practice.The term Hinayana (smaller Vehicle) appeared only much later, around the first century CE, when teachings of a different nature appeared which were called Mahayana (greater Vehicle).
In India, non-Mahayana or Hinayana sects developed independent from the form of Buddhism existing in Sri Lanka. Today, there is no Hinayana tradition in existence anywhere, although Theravada could be called the tradition most like Hinayana.
MAHAYANA: The Mahayana appears to have developed between 1st Century BC. Master Nagarjuna developed the Mahayana philosophy of Sunyata (emptiness) and proved that everything is Void in a small text called Madhyamika-karika. After the 1st Century CE, the Mahayanists took a definite stand and only then the terms of Mahayana and Hinayana were introduced.
Around the first century CE, teachings of a different style appeared. The terms Mahayana and Hinayana appeared in the Saddharma Pundarika Sutra or the Sutra of the Lotus of the Good Law. Of great influence to the development of the Mahayana was Master Nagarjuna (2nd Century CE) who is known for his profound teachings on the philosophy of emptiness. About the 4th Century CE, the Masters Asanga and Vasubandhu wrote enormous amount of works on Mahayana. The Mahayana teachings were mainly written down in Sanskrit, and are now called the Mahayana Sutras.
The Mahayana philosophy is based on the older tradition and fully accepts these teachings, but not all traditional interpretations. The Mahayana teaches instead that every sentient being (being with a mind) can become a Buddha, the only thing preventing our full enlightenment is the failure to improve one's own actions and state of mind. The Mahayana tradition claims that all their sutras have been taught directly by Shakyamuni Buddha or have at least been inspired by the Buddha.
TANTRAYANA: Around the 6th century AD, within the Mahayana tradition the tantrums or tantric texts emerged. Based firmly on the Hinayana and Mahayana tradition, the actual philosophy differs only slightly from the Mahayana, but the practices can be quite different. Prior to engaging in tantric practices, a proper understanding of the Hinayana and Mahayana philosophy is considered essential. Only then should one obtain initiation or permission from a qualified tantric master to do a specific tantric practice. Tantric practices are psychologically very profound techniques to quickly achieve Buddhahood. This is considered important, not for oneself, but because as a Buddha one has the best achievable qualities to help others. The motivation is: 'the faster I can achieve Buddhahood, the sooner I can be of maximum benefit to others'.