They are venerated especially in Vaishnavism, which regards Lord Vishnu as the Supreme entity.
Many modern academics place the Alvar date between 5th century to 10th century CE. However, traditionally the Alvar are considered to have lived between 4200 and 2700 BCE.
The devotional outpourings of alvars, composed during the early medieval period of Tamil history helped revive the Bhakti movement through their hymns of worship to Vishnu and his avatars. They praised the Divya Desams, 108 abodes (temples) of these Vaishnava deities.
The poetry of the alvars echoes bhakti to God through love, and in the ecstasy of such devotions they sang hundreds of songs which embodied both depth of feeling and felicity of expressions.
The collection of their hymns is known as Divya Prabandha.
The Bhakti literature that sprang from alvars has contributed to the establishment and sustenance of a culture that broke away from the ritual-oriented Vedic religion and rooted itself in devotion as the only path for salvation.
In addition they helped to make the Tamil religious life independent of a knowledge of Sanskrit. As part of the legacy of the alvars, five Vaishnava philosophical traditions (sampradayas) have developed at the later stages.