No other Hindu god has as many devotees as Vishnu. Hindu religious books portray him reclining comfortably on the serpent Sheshnag. Whose thousand-headed hood provides an umbrella over him. His consort, Lakshmi, is seated besides him he is sometimes depicted sleeping on the coils of the serpent.
The name Vishnu is derived from the root word vish, which means to pervade. As a god, Vishnu pervades all things and being, resides in the latter as the soul- the life force. Once the life force withdraws, the body perishes, by extension, this makes every being a home of god.
Vishnu is usually depicted with four arms, though sometimes he may even have more than this number. The many arms of Hindu deities are symbolic of the god's manifold powers. Whereas we have limited abilities, a god's power is unlimited, signified by the many hands that hold a variety of attributes and perform myriad activities, often simultaneously. According to noted Indologist Alain Danielou "the image of a deity is merely a group of symbols."
Vishnu finds his earliest mention in the Rig Veda, the most ancient book in the world. Here he appears as a solar deity. The Vishnu of the Rig Veda is a manifestation of light, whose head was, by a trick of the gods, severed from his body. This severed head is believed to have become the sun. Further in the Veda, Vishnu is a friend and associate of Indra, god of rain, thunder, and storm. Together, Vishnu the sun and Indra the rain, take on the demon Vritra, who personifies drought. Indra and Vishnu both are described as Vritrahan or the killer of Vritra. This potent combination forms an awesome ensemble of fertilizing powers. The Vedic connotations of Vishnu are discernable also in the etymology of his name which is derived form the root 'vish' , which means to spread, or in other words all-pervading. Indeed in the Vedas he is the all-pervading sun, whose rays envelop the earth, as does Vishnu himself, in his role as protector of the world.