Question: Can Vishnu be classified as Demigod? (When I am listing all the demigods to these kids)
Answer by Romapada Swami:
No, Vishnu is not one among the demigods, but is the Supreme Personality of Godhead. The demigods are empowered administrators of material affairs, and are like different assistants or limbs of the Personality of Godhead, something like the different cabinet ministers are to the Chief Executive of State.
As mentioned before, demigods are living entities, like any of us, who have but achieved that post by virtue of their exalted pious activities. They are within the covering of this material world, and are subject to birth, death and transmigration to other bodies, although their lifespan and opulence are fabulously far greater than human beings. Vishnu, however, is eternal, beyond this material world, and is the master of all demigods and human beings.
The demigods derive their power from Vishnu; He is their energetic source, and thus not in the same category as an administrative demigod. (Please refer to Bg As It Is, Chapter 3 Texts 10, 11, and 12)