Yoga and Buddhism are sister traditions which evolved in the same spiritual culture of ancient India. They use many of the same terms and follow many of the same principles and practices. For this reason it is not surprising that many of us born in the West, particularly after an initial exposure, are apt to regard Yoga and Buddhist teachings as almost identical.
However, the tendency to find commonality between these two great spiritual traditions is not limited to the West. Swami Vivekananda, the first great figure to bring Yoga to the West, examined the Buddhist Mahayana scriptures (Sutras) and found their key teachings and those of Vedanta that he followed to be ultimately in harmony. In recent years with the influx of Tibetan refugees into India, including the Dalai Lama, there has been a new dialogue between the two traditions that is bringing about greater respect between them. Tibetan Buddhists often appear at Hindu religious gatherings and partake in all manner of discussions.
Nor is the attempt to connect the two traditions limited to modern times. Various synthetic Hindu-Buddhist teachings have existed through history. Buddha himself was born a Hindu and some scholars have argued that Buddhism as a religion apart from Hinduism did not arise until long after the Buddha had passed away. A Shiva-Buddha teaching existed in Indonesia in medieval times, and for many Tantric Yogis it is difficult to tell whether they were Hindus or Buddhists. Buddha became accepted as an avatar of Vishnu for the Hindus during the medieval period, and most Hindus still consider that we live in the age of the Buddha-avatar. Most Hindus accept Buddha as a great teacher, even if they do not accept all Buddhist teachings.
Yet, similarities and connections aside, the two traditions have had their differences, which have not always been minor. Such synthetic trends did not exclude disagreements and debates between the two traditions. Nor did they ever succeed in fully uniting them. Their traditions and lineages remain separate to the present day. Generally the Hindu Yoga tradition sought to absorb Buddhism into itself by reinterpreting Buddha in a Vedantic light. Buddhism however strove to maintain its separate identity by stressing its disagreements with Vedic theism or the Vedic recognition of a higher Self. Most Hindu and Buddhist teachers, including those of the different Yoga schools of Hinduism and Tibetan Buddhists, have found it necessary to discriminate their doctrines, particularly on subtle levels of practice and insight. Refutations of Buddhist teachings are common in yogic texts and refutations of yogic and Vedantic teachings are common in Buddhist texts. So while we can honor the connections between these two systems, we cannot overlook their differences either.
Excerpt From American Institute Of Vedic Studies Article, Yoga And Buddhism: Similarities And Differences, By David Frawley