Daityas, demons 'सुर' means 'gods' and अ-सुर means 'demons'. As enemies of the gods, the demons sometimes waged wars with the gods. In the Rigveda, the same word 'असुर' is used for deities with power and vitality. While in the Puranic period the meaning of 'असुर' meaning 'demons' has come into vogue, because asuras are cruel and full of violence. Smriti and Srimadbhagavadgita say, 'work, anger and greed. These are the three gates of hell. They are soul destroyers. While the asuras are engrossed in the demonic tendencies of these three. So they are considered as 'असुर'. His work is never satisfied. They are engrossed in the desires for material pleasures.