The Aranyakas were written in Forests and are concluding parts of the Brahmans. Aranyakas don’t lay much emphasis on rites, ritual and sacrifices but have philosophy and mysticism. So they have moral science and philosophy. It also provides the details of the rishis who lived in jungles.
Aranyakas were written mainly for the hermits and students living in the jungles. Please note that Aranyakas are the concluding portion of the Brahmanas or their appendices. They lay emphasis not on sacrifices but on meditation. They are in fact, opposed to sacrifices and many of the early rituals. Their stress is on moral values. They form a bridge between way of work (karma marga) which was the sole concern of the Brahmanas and the way of knowledge (gyan marga) which the Upanishads advocated.
- The Aitareya Aranyaka is appended to the Aitareya Brahmana of the Rig-Veda. The Sankhyayana or Kaushitaki Aranyaka is the concluding portion of the Kaushitaki Brahmana of the Rig-Veda.
- In the black YajurVeda, the Taittriya Aranyaka is only a continuation of the Taitttriya Brahamana. In the white YajurVeda, the 14th book of the Satapatha Brahmana is in name only an Aranyaka- the Brihdarnayaka.
- For the SamaVeda, the only Aranyakas are the first Aranyaka-like sections of the Chhandogya Upanishad, which belongs to the Tandyamaha Brahmana, and the Jaimniya Upanishad Brahmana, which is nothing but an Aranyaka of the Jaiminiya or Talavakara school of the SamaVeda and comprises the well Known Kena (or Talvakra) Upanishad.
There are no Aranyakas of Atharvaveda