This document provides an overview of Buddhism in South Asia, including its origins and key figures, teachings, and branches. It describes how Siddhartha Gautama founded Buddhism based on his realization of the Four Noble Truths and Eightfold Path after rejecting a life of luxury and extreme asceticism. The document outlines the main branches of Buddhism - Theravada, Mahayana, Tibetan, and Zen - and some of their distinguishing characteristics and geographic distributions.