Anga referred to a region in what is now Bihar, Jharkhand, West Bengal states of India, and Lipi meant script.  The Anga Script is mentioned in an ancient Sanskrit language Buddhist book the "Lalitvistar" (ललितविस्तर), which names Anga Lipi relatively early in the list of 64 scripts known to the Buddha. The script was specific to the Anga region, or Anga Mahajanapada, and was among those known to Buddha. The script was mentioned as the fourth most important script of Ancient India in one version. Arthur Coke Burnell thought that some of the sixty four scripts mentioned in "Lalitvistar" were mythical, but he considered some, including Dravid, Anga and Banga, to be real, though not appearing as distinct alphabets until the 9th or 10th century CE. (Burnell regarded this passage as a late interpolation.)
Anga Lipi and Banga Lipi might have been derived from Brahmic, with some regional characteristics. This supports the belief that the development of local characteristics in alphabets was continuing from earlier times.
It reflects the early development of local variants of Indian alphabets.