Indra is the King of the demi-gods or Devas and Lord of Heaven Hindu mythology. He is also the God of War, Storms, and Rainfall.
Indra is one of the chief deities in the Rigveda. He is celebrated as a demiurge who pushes up the sky, releases dawn (Ushas) from the Vala cave, and slays Vṛtra; both latter actions are central to the Soma sacrifice. On the other hand, he also commits (like Zeus) many kinds of mischief (kilbiṣa) for which he is sometimes punished. He has many epithets, notably vṛṣan the bull, and vṛtrahan, slayer of Vṛtra and maghavan "the bountiful'. Indra appears as the name of an arch-demon in the Zoroastrian religion, while his epithet Verethragna appears as a god of victory.
In Puranic mythology, Indra is bestowed with a heroic and almost brash and amorous character at times, even as his reputation and role diminished in later Hinduism with the rise of the Trimurti. Indra is also called Śakra frequently in the Vedas and in Buddhism.

Budddhist Definition

In Buddhism and Jainism, Indra is commonly called by his other name, Śakra or Sakka, ruler of the Trāyastriṃśa heaven. However, Śakra is sometimes given the title Indra, or, more commonly, Devānām Indra, "Lord of the Devas". The ceremonial name of Bangkok claims that the city was "given by Indra and built by Vishvakarman." The provincial seal of Surin Province, Thailand is an image of Indra atop Airavata.