They deal with practical methods of worship like mantras, tantras and yantras. They describe how to construct temples, idols, charms and spells, mystic diagrams, social rules and public festivals. Agamas are of three types: 1. Vaishnava Agamas which glorify lord Vishnu as the main deity. 2. Saiva Agamas which treat lord Siva as the main deity and 3. Sakta Agamas which consider goddess Devi (or Lalitha) as the mother of the Universe.