So far as the origin of the word Indus is concerned, Scholars are of the opinion that the name "Indus" is the origin of the word "Hindu." The original Indian name of the river is Sindhu. The ancient Iranians had difficulty in pronouncing an initial sibilant "s" and changed it to an aspirate sound "h", hence, "H-indu" instead of "S-indhu." The Greeks referred to the river as the "Indos," and the later Arabs referred to it as "al-Hind." Eventually the name came to be applied to the people of the subcontinent, namely, the "Hindi," the "Hindus" and the "Indians." In ancient times Indians themselves referred to their country as Bharata-varsha (the "land of the sons of Bharata," a ruler),
It is believed that the Indus valley civilization belonged to the copper stone age as the presence of iron tools and implements has not yet been established at any part of this civilization.
Archaeological excavation indicates that the Indus valley civilization could have flourished in about 300 B.C. much before the existence of other civilizations. Discovery of seals from Ur, Sumeru and other areas of Mesopatamia civilization indicates that Harappan people had trade relation with the Mesopatamian people. This suggests that the civilization flourished from about 3000 BC to 1500 BC.
Anthropological investigation and examination of the human remains shows that four racial types existed in this civilization. They were the proto - Australiod, Mediterranean, Alpine and the Mongoloid. Archaeological excavation reveal the existence of various racial types. Of all these the existence of the Dravidian race holds its relevance owing to its wide spread acceptance. Scholars are differed in their opinion about the race of Indus people. Some say it is of the Aryans while others opine that it is of the Dravidians.