Hinduism is more ritualistic and complex. People have castes and can achieve enlightenment only over multiple lives. Buddhism isn't as ritualistic, and people of any caste can achieve enlightenment in just one life. Buddhists also believe in a certain set of doctrines from the Buddha called the Four Noble Truths and the Eightfold Path.
South Asia is often called a subcontinent. It's bordered by mountains to the north and west, and it also experiences monsoons, which are seasonal winds that cause rainy seasons and dry seasons.