Buddhism generally falls under either Theravada Buddhism or Mahayana Buddhism. The various schools of Buddhism each have their own central concepts and do not always share the same philosophies. However, both Theravada and Mahayana schools accept the Buddha as their teacher, the Middle way, the Four Noble Truths, the idea that lay people can become enlightened, and that becoming a Buddha is the highest attainment.
The Theravada school of Buddhism is the oldest branch and is currently active in Sri Lanka and South East Asia. The centrality of this branch in India, however, has declined in existence. The Pali Canon is the main doctrine of Theravada. The texts of the Pali Canon are considered to be the earliest literature of Buddhism.
The Mahayana School of Buddhism came after Theravada in India from the 5th century C.E. It was under the Gupta Dynasty that Mahayana emerged as a branch of Buddhism. This branch recognizes all of the Mahayana Sutras, with some of the sutras being a manifestation of the Buddha. Mahayana Buddhism is primarily practiced in China, Japan, Korea, Singapore, Vietnam and various parts of Russia. Tibetan Buddhism is also part of the Mahayana branch.
The other third major branch of Buddhism is the Vajrayana school which spread to China, Tibet and Mongolia.