The Upanisads – Relation To The Vedas-Rg Veda

The Vedas are a large body of religious texts originating in ancient India. Composed in Vedic Sanskrit are the oldest layer of Sanskrit literature and scriptures of Hinduism. The Upanishads are late Vedic Sanskrit texts of religious teachings and ideas still revered in Hinduism.
Vedas were composed over a time period ranging from 1200 to 400 B.C.E
The Upanishads were written over a time period ranging from 700 to 400 B.C.E
There are 4 different Vedas – Rig Veda, Sama Veda, Yajur Veda, Atharva Veda.