Who Lord Vishnu is
Vishnu is one of the three principal deities of the Hindu trimurti — alongside Brahma the creator and Shiva the dissolver — and is venerated as the preserver and sustainer of the cosmos. Where Brahma’s role is brief and confined to the moment of cosmic emanation, and Shiva’s role unfolds at dissolution, Vishnu’s work is the long, patient, ongoing maintenance of dharma across cycles of cosmic time.
He is most often depicted with four arms, holding the shankha (conch), chakra (discus), gada (mace), and padma (lotus). He reclines on the serpent Sheshanaga upon the cosmic ocean, with Lakshmi at his feet, and from his navel rises the lotus that holds Brahma. His mount is Garuda, the great eagle.
The avatars
Vishnu’s most distinctive theological feature is the doctrine of avatara — descent. When dharma weakens and adharma rises, Vishnu takes form on earth to restore balance. The classical reckoning lists ten such descents, the Dashavatara: Matsya the fish, Kurma the tortoise, Varaha the boar, Narasimha the man-lion, Vamana the dwarf, Parashurama the warrior-sage, Rama, Krishna, Buddha, and the future Kalki. Each avatar carries its own scripture, festival, and devotional tradition; Rama and Krishna in particular have become the focal deities of vast sub-traditions in their own right.
This means that worship of Vishnu often passes through one of his avatars. The Bhagavad Gita is Krishna’s sermon to Arjuna; the Ramayana is Rama’s story; both are, in the Vaishnava reading, encounters with Vishnu in human form.
Festivals and worship days
Thursday is the conventional weekly day for Vishnu worship. Ekadashi — the eleventh day of each lunar fortnight — is observed as a fasting day across Vaishnava traditions. Major festivals include Vaikuntha Ekadashi (December–January), Rama Navami (Rama’s birthday, March–April), Janmashtami (Krishna’s birthday, August–September), and Narasimha Jayanti (April–May).
What devotees seek
Vishnu is invoked for protection, for the preservation of order in family and society, for stability in the face of upheaval, and for the long view — the trust that dharma will, eventually, prevail. The most beloved Vishnu hymn collected here is the Om Jai Jagdish Hare aarti, sung in households across India at the close of the evening puja.