What are the differences between the two major Schools of Buddhism, i.e. Theravada and Mahayana?

 Theravada means the School which maintains the original teaching of the Buddha. Its root can be traced back to the First Council which was held soon after the Buddha’s passing away; hence it is considered the oldest School. Mahayana came much later, roughly speaking, about 600 years after the Buddha’s time. Vajarayana or Tantrayana developed from the Mahayana approximately 400 years after the beginning of the Mahayana.

  Geographically, Theravada is more prevalent in Sri Lanka, Burma (Myanmar), Thailand, Cambodia and Laos while Mahayana is prevalent in China, Japan, Korea, Vietnam, Nepal and Tibet.

Theoretically both Schools share the fundamental teachings of the Four Noble Truths, etc. but Mahayana developed many more Sutras as elaboration of the original teaching. Among the important Mahayana Sutras are Saddharmapundarika-Sutra, Vimalakirtinirdesa-Sutta, Bhaisajyaguru-Sutra, etc. However, the Vinaya (monastic disciplines) of both Schools remain very similar. The difference in practices is primarily due to different sociological and geographical contexts.