The Vaishnava Agamas or Pancharatra Agamas glorify God as Vishnu.

The Saiva Agamas glorify God as Shiva and have given rise to an important school of philosophy known as Saiva-Siddhanta, which prevails in South India, particularly in the districts of Tirunelveli and Madurai.

The Sakta Agamas or Tantras glorify God as the Mother of the Universe, under one of the many names of Devi (Goddess).

The Agamas do not derive their authority from the Vedas but are not antagonistic to them. They are all Vedic in spirit and character. That is the reason why they are regarded as authoritative.

The Vaishnava Agamas

The Vaishnava Agamas are of four kinds:

1. The Vaikhanasa
2. Pancharatra
3. Pratishthasara
4. Vijnana-lalita

The Brahma, Saiva, Kaumara, Vasishtha, Kapila, Gautamiya and Naradiya are the seven groups of the Pancharatras. The Naradiya section of the Santi Parva of the Mahabharata is the earliest source of information about the Pancharatras.

Vishnu is the Supreme Lord in the Pancharatra Agamas. The Vaishnavas regard the Pancharatra Agamas to be the most authoritative. They believe that these Agamas were revealed by Lord Vishnu Himself. Narada-Pancharatra says: “Everything from Brahma to a blade of grass is Lord Krishna”. This corresponds to the Upanishadic declaration:

“All this is, verily, Brahman-Sarvam, Khalvidam Brahma”.

The following extract is from The Mahabharata, Santi Parva
Section CCCXL

Bhishma continued: Narada also, endued with great energy, having obtained the high favour that he had solicited, then proceeded with great speed to the retreat called Vadari, for beholding Nara and Narayana. This great Upanishad, perfectly consistent with the four Vedas, in harmony with Sankhya-Yoga, and called by him by the name of Pancharatra scriptures, and recited by Narayana Himself with His own mouth, was repeated by Narada in the presence of many listeners in the abode of Brahma (his sire) in exactly the same way in which Narayana (while that great God had showed Himself unto him) had recited it, and in which he had heard it from his own lips.

There are two hundred and fifteen of these Vaishnava texts:

Isvara, Ahirbudhnya, Paushkara, Parama, Sattvata, Brihad-Brahma and Jnanamritasara Samhitas are the important ones.

The Saiva Agamas

The Saivas recognise twenty-eight Agamas, of which the chief is Kamika. The Agamas are also the basis of Kashmir Saivism which is called the Pratyabhijna system.  The latter works of Pratyabhijna system show a distinct leaning to Advaitism (non-dualistic philosophy).

The Southern Saivism, i.e., Saiva Siddhanta, and the Kashmir Saivism, regard these Agamas as their authority, besides the Vedas.

Each Agama has Upa-Agamas (subsidiary Agamas). Of these, only fragmentary texts of twenty are extant.

Lord Siva is the central God in the Saiva Agamas. They are suitable to this age, Kali Yuga. They are open to all castes and both the sexes.

The Sakta Agamas

There is another group of scriptures known as the Tantras. They belong to the Sakta cult. They glorify Sakti as the World-Mother. They dwell on the Sakti (energy) aspect of God and prescribe numerous courses of ritualistic worship of the Divine Mother in various forms.

There are seventy-seven Agamas. These are very much like the Puranas in some respects. The texts are usually in the form of dialogues between Siva and Parvati.

In some of these, Siva answers the questions put by Parvati, and in others, Parvati answers, Siva questioning.

Mahanirvana, Kularnava, Kulasara, Prapanchasara, Tantraraja, Rudra-Yamala, Brahma-Yamala, Vishnu-Yamala and Todala Tantra are the important works.

The Agamas teach several occult practices some of which confer powers, while the others bestow knowledge and freedom. Sakti is the creative power of Lord Siva. Saktism is really a supplement to Saivism.

Among the existing books on the Agamas, the most famous are the Isvara-Samhita, Ahirbudhnya-Samhita, Sanatkumara-Samhita, Narada-Pancharatra, Spanda-Pradipika and the Mahanirvana-Tantra.