Vedic mythology refers to the mythological aspects of the historical Vedic religion and Vedic literature, alluded to in the hymns of the Rigveda. The central myth at the base of Vedic ritual surrounds Indra who, inebriated with Soma, slays the dragon (ahi) Vrtra, freeing the rivers, the cows and Dawn.
Vedic lore contains numerous elements which are common to Indo-European mythological traditions, like the mythologies of Persia, Greece, and Rome, and that of the Celtic, Germanic, Baltic and Slavic peoples. The Vedic god Indra in part corresponds to Dyaus Pitar, the Sky Father, Zeus and Jupiter or Perun. The deity Yama, the lord of the dead, is Yima of Persian mythology. Vedic hymns refer to these and other deities, often 33, consisting of 8 Vasus, 11 Rudras, 12 Adityas, and the late Rigvedic Prajapati. These deities belong to the 3 dimensions of the universe/heavens, the earth, and the intermediate space. Some major deities of the Vedic tradition include Indra, Surya, Agni, Vayu, Varuna, Mitra, Aditi, Yama, Soma, Sarasvati, Prithvi, and Rudra.
The Vedas in Puranic mythology
The Vishnu Purana attributes the current arrangement of four Vedas to the mythical sage Vedavyasa. Puranic tradition also postulates a single original Veda that, in varying accounts, was divided into three or four parts. According to the Vishnu Purana (3.2.18, 3.3.4 etc.) the original Veda was divided into four parts, and further fragmented into numerous shakhas, by Vishnu in the form of Vyasa, in the Dvapara Yuga; the Vayu Purana (section 60) recounts a similar division by Vyasa, at the urging of Brahma. The Bhagavata Purana (12.6.37) traces the origin of the primeval Veda to the syllable aum, and says that it was divided into four at the start of Dvapara Yuga, because men had declined in age, virtue and understanding. Another view is that the original veda was called Pranava Veda nad is attributed to Brhamarishi Mayan, the great architect. This Veda is held by Vaastu Vedic Trust. In a differing account, the Bhagavata Purana (9.14.43) attributes the division of the primeval veda (om) into three parts to the monarch Pururavas at the beginning of Treta Yuga. Rig, Sama, Yajur and Atharva constitute the "Four Vedas". The Rig Veda (mantras) is a collection of inspired songs or hymns and is a main source of information on the Rig Vedic civilization. The Sama Veda (songs) is purely a liturgical collection of melodies (saman). The hymns in the Sama Veda, used as musical notes, were almost completely drawn from the Rigveda and have no distinctive lessons of their own. The Yajur Veda (rituals) is also a liturgical collection and was made to meet the demands of a ceremonial religion. The Atharva Veda (spells) is completely different from the other three Vedas and is next in importance to Rigveda with regard to history and sociology.