In that aspect as the altar fire, Agni-Jataveda was perceived to be the means through which his worshippers were to gain knowledge/wisdom/understanding (veda) of all existence (jata).
In an extended sense, the altar fire/Agni-Jataveda was then also perceived to be the hypostasis of the inspiration that engendered the Vedas themselves.
This exact sense of word appears to have been lost very early,[1] and there are numerous speculations on the nature of the Jatavedas in the commentaries of the late Vedas and the Brahmanas.
According to Brahma puran, Jataveda is the brother of Agni who used to deliver havishya (offerings to Yajna).
He was killed by Madhu, son of Diti, due to which he himself was posted as the new Jataveda by Devas and Rishis.