Vishnu also known as Mahavishnu is the second deity of the Hindu Trinity. He is the one who protects and sustains the created universe. Vishnu means one who pervades and entered everything. He is the inner cause and power of the universe. He is popularly known as Narayana or Ranganatha.

Narayana means:

“One who has made the causal waters his abode. “
“One who is the abode of all human beings. “
“One who has made the heart of human beings his abode. ”
“One who is the final goal of all human beings”
Ranganatha the Supreme God is depicted as; he falls asleep on his bed of great serpent Adhisesha, which is floating on the ocean of milk (Ksirasamudra – Thiruparkadal). One of his legs is resting on the lap of his consort Lakshmi, who is gently pressing it. A lotus spring forth from his navel along with god Brahma seated on it.

Vishnu is described as Nilameghashyama, of a dark blue hue like that of the rain-bearing cloud. Commonest form of the Vishnu icon has one face, four arms holding Sankha(Conch), Chakra (Discus), Gadha(Mace), Padma(Lotus and wears a necklace with the famous gem of Kaustubha dangling on the lock of hair Srivatsa, on the left chest. He is also wearing the garland of flowers and gems by name Vaijayanthi.

Lord Vishnu, whose duty is to preserve this world, often incarnates himself. Ten such incarnations popularly known as Dasa-Avatar. Whenever Dharma (Righteousness) declines he bodies himself forth to restore the balance in the world.

Matsya (Fish Incarnation), Kurma (The Tortoise), Varaha (The Boar), Narasimha (Man-Lion), Vamana (The Dwarf), Parasurama (Brahmana with Battle Axe), Sri Rama (The King), Balarama (Brother of Krishna), Krishna (One who preached Bhagavat Gita) and the tenth Kalki (Warrior on the White Horse back) yet to come are the Dasa-Avatars of Lord Vishnu.