Like Dvaravati, Srivijayan culture was influenced by India more than any other culture. This is especially true when it comes to religion. The primary (main) religion of the Srivijayan kingdom was Mahayana Buddhism, unlike the Dvaravati kingdom, whose primary religion was Theravada Buddhism. Mahayana Buddhism was brought to the region in the 5th century by monks from northern India who went to Sumatra in with the goal of spreading their religion to foreign lands.
Srivijaya actually became a well-known place to study Buddhism and Sanskrit (the language which the Mahayana Buddhist text were written in). Chinese monks actually went there to study before making their journey to India, the homeland of Buddhism. In fact, at one point there were over 1000 Buddhist monks living in Palembang alone.
Although Mahayana Buddhism was the primary religion of Srivijaya, they also combined aspects of Hinduism and animism into their Buddhist practices. Hinduism is an old, polytheistic religion from India, which is even older than Buddhism. Animism refers to the belief in spirits and ghosts who live all around us.