While in Saivite shrines, it is the Shivalingam or the non-anthropomorphic form that is enshrined in the innermost sanctum, it is the iconic form of Vishnu that is center of reverence.
Sri Vaishnavism is one of the pre-eminent traditions of Hinduism. An unbroken lineage of teachers, (the Acharyas) and a wealth of literature in Tamil and in Sanskrit and the Vishishtadvaita philosophy form the backbone of the Sri Vaishnava religion.
Around 1300 years ago, during what is known as the Bhakti movement, saint poets across the country, sang verses in praise of Vishnu, glorifying the deity enshrined in temples all over India. 108 of these shrines and mythological abodes are collectively known as the Divya Desam shrines.