विष्णू हि सर्वोच्च शक्ती असून, त्रिमूर्ती ब्रह्मा, विष्णू आणि महेश यांपैकी, भगवान विष्णूचे कार्य विश्वाचा सांभाळ आणि प्रतिपाळ करणे आहे.या विश्वात जेव्हा जेव्हा राक्षसी शक्ती मानवास त्रासदायक होतात,तेव्हा श्रीविष्णू अवतार घेऊन त्यांचा नाश करतात.विष्णूचे अवतार दहा-मत्स्य, कूर्म, वराह, नरसिंह, वामन, परशुराम, राम, कृष्ण, बुद्ध आणि कल्की. ज्या ज्या वेळेस विष्णूने पृथ्वीवर अवतार घेतला त्या त्या वेळेस त्यांची पत्नी लक्ष्मीनेही अवतार घेतला, रामावतरात सीता तर कृष्णावतारात रुख्मिणी. कृष्णावतारात भगवानांनी अर्जुनाला गीता सांगितली, ज्यात जीवनातील अंतीम सत्य आहे.विष्णूला नारायण म्हणूनही संबोधतात.विष्णूचे वास्तव्य क्षीरसागरात शेशनागावर आहे. त्याचे वाहन गरूड आहे.चार हातात शंख, चक्र, गदा, पद्म आहेत.समुद्रमंथनात अमृत मिळाले असता मोहिनी रूप घेऊन ते त्यांनी देवांना मिळवून दिले. 

Vishnu,also known as Narayana is the Supreme Being or Ultimate Reality In the Trimurti, Vishnu is responsible for the maintenance or 'preservation' of the universe, with the other roles of creation and destruction being under the care of Brahma and Shiva, respectively. when powers of good and evil (gods and demons) are in contention for domination over the world. When these powers are upset Vishnu, it is believed, descends to earth, or his avatar, to equalized the powers. Further it is thought that ten such incarnations or reincarnations of Vishnu will occur. Nine descents are said to have already occurred, the tenth is yet to come. These avatars were Matsya (fish), Kurma (tortoise), Varaha (boar ), Nara-simha (man-lion), Vamana (dwarf), Parashurama (a powerful warrior), Rama, Krishna, Buddha and Kalki (white horse).  A romantic aspect of the myths, is that whenever Vishnu descends to earth he marries Lakshmi (his Goddess wife). They are destined to marry on earth as in heaven. When Vishnu is Rama, Lakshmi is born as Sita. As Krishna he marries her as Rukmini. In his cosmic form Vishnu is seen reclining on a many headed serpent called Ananta and the oceans lie subdued under him. He holds a chakra (discus) in a hand with which he maintains order in the universe. The shankha or conch was retrieved by him during the churning of the oceans, and its deep humming sound is an evocation of the sea. He holds a lotus for peace and a gada (mace) a controlling weapon. Garuda the eagle is his celestial vehicle.