In the Vedas, Indra is the king of Svarga (Heaven) and the Devas. He is the god of the heavens, lightning, thunder, storms, rains and river flows. Indra is the most referred to deity in the Rigveda. He is celebrated for his powers, and the one who kills the great symbolic evil (Asura) named Vritra who obstructs human prosperity and happiness. Indra destroys Vritra and his "deceiving forces", and thereby brings rains and the sunshine as the friend of mankind. His importance diminishes in the post-Vedic Indian literature where he is depicted as a powerful hero but one who is getting in trouble with his drunken, hedonistic and adulterous ways, and the god who disturbs Hindu monks as they meditate because he fears self-realized human beings may become more powerful than him.
Indra rules over the much sought Devas realm of rebirth within the Samsara doctrine of Buddhist traditions. However, like the Hindu texts, Indra also is a subject of ridicule and reduced to a figurehead status in Buddhist texts, shown as a god that suffers rebirth and redeath. In the Jainism traditions, like Buddhism and Hinduism, Indra is the king of gods and a part of Jain rebirth cosmology. He is also the god who appears with his wife Indrani to celebrate the auspicious moments in the life of a Jain Tirthankara, an iconography that suggests the king and queen of gods reverentially marking the spiritual journey of a Jina.
Indra's iconography shows him wielding a lightning thunderbolt known as Vajra, riding on a white elephant known as Airavata. In Buddhist iconography the elephant sometimes features three heads, while Jaina icons sometimes show the elephant with five heads. Sometimes a single elephant is shown with four symbolic tusks. Indra's heavenly home is on or near Mount Meru (also called Sumeru).
Colonial era scholarship proposed that Indra shares etymological roots with Zend Andra derived from Old High German Antra, or Jedru of Old Slavonic, but Max Muller critiqued these proposals as untenable. Later scholarship has linked Vedic Indra to the European Aynar (the Great One), Abaza, Ubykh and Innara of Hittite mythology. Colarusso suggests a Pontic origin and that both the phonology and the context of Indra in Indian religions is best explained from Indo-Aryan roots and a Circassian etymology (i.e. *inra).