The followers of Guru Nanak are known as Sikhs, a term which is derived from the Sanskrit word for 'DISCIPLE' or 'LEARNER'. Guru Nanak was the founder of Sikhism, a monotheistic religion that originated in the Punjab region of India in the 15th century. The core beliefs of Sikhism include faith in one God, service to humanity, and living an honest and ethical life. Sikhs follow the teachings of the ten Gurus, the holy scriptures known as the Guru Granth Sahib, and the teachings of the Khalsa.