The Indo-Europeans are called Aryans although the term Arya is found mainly in the eastern Indo-European languages. This term may indicate the culture shared by the Avesta and the Rig Veda. The two terms Indo-Iranian and Indo Aryan is frequently used. The term Indo-Iranian is used to signify the undifferentiated language which was spoken by the Aryans comprising the Indians and Iranians before their separation. The term Indo-Aryan means the speech and its speakers who existed in India sometimes are termed as Proto-Indian to denote the same. The term Arya occurs in both the Rig Veda and Avesta. Since Afghanistan was occupied by the Indo Aryans and the Iranian Aryans for some time, a part of this country came to be known as Araiya or Haraiva. In the sixth century BC King Darius I of Persia called himself an Aryan. In the Rig Veda the term Arya connotes a cultural community. Speakers of both the Indo Aryan and the Indo Iranian languages are called Aryans. The Avesta mentions the country of the Aryans where Zoroastrianism began. This might indicate the 'Aria' or 'Ariana' mentioned by classical writers. It covered a large area including Afghanistan and a part of Persia. It also included parts of Bactria and Sogdia to its north. Megasthenes speaks of Arianois as one of the three people inhabiting the countries adjacent to India.
In the Rig Veda the worshippers of Indra were called arya. When this text speaks of the struggle between the Aryans on the one hand and the dasas and the dasyus on the other it does not consider the former to be indigenous and the latter to be foreigners. The struggle takes place between two cultures one observing the vrata and the other violating it. At that stage there is no perception of India as a country or a nation and therefore the notion of indigenous and foreigner do not arise. On the basis of skin colour some hymns of the Rig Veda depict Aryans to be of a separate community. Their enemies are described as black skinned.