Divya Desams are temples where Azhwars worshipped Lord Vishnu, as the presiding deity. Their divine hymns are popularly known as Nalayira Divya Prabantham. The Divya Prabandham is in the form of adoration of the deities of 108 temples (Divya Desams). The verses in simple Tamil explain what the Vedas, Upanishads and Vyasa's Brahmasutras say.

It was the scholar-saint Nathamuni who, in the 10th century, retrieved and compiled this bhakti treasure, which is the pride of Tamil classical literature. The Sri Vaishnava guru parampara (inheritance order of the preceptors) is held to commence from Lord Sri Narayana himself, and to centre, rightly so, around Sri Nathamuni and his grandson Sri Yamunacharya.

The Naalaayira Divya Prabhandam is classified as under:

Mudal Aayiram or First Thousand contains 947 songs. It includes: Periyaazhwar Thirumozhi (473 songs) of Periazhwar, including Thiru Pallaandu.
Tiruppaavai by Andal (30 songs)
Naachiyaar Thirumozhi by Andal (143 Songs)
Perumaal Thirumozhi by Kulasekhara Azhwar (105 songs)
Thiruchanda Virutham by Tirumazhisai Azhwar (120 songs)
Tirumaalai by Thondaradi Podiazhwar (45 songs)
Tiruppalli Ezuchi by Thondaradi Podiazhwar (10 songs)
Amalaanathi Piraan by Thirupaanazhwar (10 songs)
Kanninum Siru Thaambu by Madhurakavi Azhwar (11 songs)

Periya Thirumozhi or Greater Hyms contains 1134 songs, all sung by Thirumangai Azhwar. It is divided into Periya Thirumozhi (1084 songs), Thiru Kurun Thaandagam (20 songs) and Thiru Nedun Thaandagam (30 songs).

ThiruvaaiMozhi or Divine Hyms were sung by Nammazhwar and faithfully written down by his disciple Madhurakavi Azhwar. It contains 1102 songs.
Iyerpaa is the last division in the Divya Prabandam and contains the following: Mudal Thiruvandaadhi by Poigai Azhwar (100 songs)

Irandaam Thiruvandaadhi by Bhootath Azhwar (100 songs)
Moondraam Thiruvandaadhi by Pey Azhwar (100 songs)
Naanmugan Thiruvandaadhi by Thirumazhisai Azhwar (96 songs)
Thiru Virutham by Nammazhwar (100 songs)
Thiru Vaasiriyam by Nammazhwar (7 songs)
Periya Thiru Andaathi by Nammazhwar (87 songs)
Thiruvezukootrirukkai by ThirumangaiAzhwar (1 song)
Siriya Thirumadal by ThirumangaiAzhwar (40 songs)
Periya Thirumadal by ThirumangaiAzhwar (78 songs)

The last piece in the collection is Ramanuja Nootranthaathi (108 songs) of Amudhanar, and it was added to the text compiled by Naathamuni.

Vaishnava Agamas: The Agamas are texts derived from various concepts in the Vedas dealing with worship. The Agamas describe in detail the various forms of God, the methods of temple worship, home worship, fire sacrifices offerings and other related ideas. The Sri Vaishnava Sampradaya accepts two Agamas only as authoritative and non-conflicting with Vedas. They are: Pancharatra Agama & Vaikhanasa Agama Of the two Pancharatra is the pradhana or main source of authority for the Sri Vaishnavas. Vaikhanasa Agama is highly utilized for temple worship only and is restricted to a certain group of Vedic priests.

Vishnu is the Supreme Lord in the Pancharatra Agamas. The Vaishnavas regard the Pancharatra Agamas to be the most authoritative. They believe that Lord Vishnu Himself revealed these Agamas.

The Asura Madhukaitaba seized the Vedas from Lord Brahma and hid himself into the sea. Lord Vishnu took the Matsyavathara fought with the Asura within the sea, killed him and got back the Vedas and restored them to Brahma. It took 5 days for the Lord for this purpose. Without the Vedas, the world became dark, not knowing how to worship the Lord. So Lord Vishnu divided Himself into two, one as Guru or teacher and the other as Sishya or disciple. The guru taught the disciple the methods of worshipping God for five nights. Hence the teaching was called Pancharatra or work of the five nights. They are all about the methods of worship.

Like the Pancharathra Samhitas, there is another kind of Samhitas called the Vaikhanasa Samhithas, prescribing the methods of worship in temples. They were taught to Sage Vikasana by MahaVishnu and through him to the Sage's descendants. There is not much of a difference between the two, except chanting of some different manthras during the worship..

Pancharatra is more universal and used extensively by the Sri Vaishnava Acharyas to propagate worship of Vishnu among the masses.

Worship protocol: While in all of the Divya Desams in Tamilnadu (with the exception of Nilattingal Tundam, Kalvanoor, Tiruvattaaru and Tiruvanpatisaaram) the Vaishnava Agamic (Pancharatra or Vaikanasa) protocol of worship is followed, the Kerala Tantram is followed in the Divyadesams in Malainadu. Worship services at Badrinath follow a protocol established during the period of Adi Sankaracharya.

Perumal: The Tamil word “perumal” is used by Vaishnava tradition to denote the Supreme Divinity as well as the idol – “arca” -- of the Divine. The two words which compose to make “perumal” areperum, which means ‘the great’ ‘the gigantic’ ‘the supreme’ and “al” which means ‘personality’. The corresponding Sanskrit word is ‘purushottama’. The sandals of Perumal are known as theSathaari. TheSathaari is like a crown placed reverentially on the heads of devotees who receive it with humility

Two branches of Vaishnavas: In Srivaishnava school itself; two branches of thought had emerged between the time of Sri Ramanuja and that of Sri Vedanta Desika whose contemporary was Pillai Lokacharya. They are called Vadakalai (Northern) and Tenkalai (Southern) though in reality there is no geographical polarization to justify their nomenclature.

Possibly, this is due to greater importance ascribed by the former to the Vedas, which were in Sanskrit, a language prevalent in the Northern part of India, while the latter stressed the importance of the Divya Prabandams of Alwars, which were in Tamil, the language prevalent in Southern part of India. This distinction has, in fact, no meaning since both in temple worship and in the hearths and homes the two streams have been so integrated and observed by both the branches.

Swami Sri Vedanta Desika is generally regarded as representing the so-called ' Vadakalai' sect. But, since he has produced monumental works in both the ' Northern Sanskrit' and the ' Southern Tamil', he and his followers could more appropriately be called ' Ubhaya Kalai' (both Kalais) rather than mere ' Vadakalai'.

As long as Ramanuja was alive, Sri Vaisnavas attached equal importance to both the Sanskrit and Tamil sides of their tradition. They stayed together as one group following the beliefs and practices of the Acharyas and the Azhwars. After Ramanuja however, certain teachers tended to emphasise the Sanskrit Vedas, while others emphasised the Tamil Divya Prabandhanas. The move towards the Tamil Divya Prabandhams was natural because Tamil was the mother tongue of the people, but the consequences of this division between the Sanskrit and Tamil sides of the tradition, led to differences of philosophical interpretation. This in turn eventually led to a split among the SriVaisnavas into two groups, the so-called Northerners, the Vadakalai, and the so-called southerners, the Tenkalai.

In theory the Vadakalai places greater stress on the Sanskrit side of the tradition, whereas the Tenkalai give more emphasis to the Tamil side. In actual practice however, the Vadakalai and Tenkalai connect themselves to Ramanuja through descendent lines running through different theologians. The Vadakalai connect them through Vedanta Desika, where as the Tenkalai connect them through Pillailokacarya.