What are the differences between Indus Valley Civilization and Vedic civilization?

The distinction, to the extent it exists, would be between
the earliest residents of the Indus River valley, the Harappan people; and the later
Aryans who moved into India and spread far beyond the Indus
valley.

The Harappan people, also known as Dravidians, are
the earliest known of the Indian civilizations. Because the remains of the cities are
underwater and because their language has not yet been deciphered, most that is known of
them is speculation. It is known that they were fairly advanced with class distinction,
and eventually encompassed a large area larger than Mesopotamia, in fact covering all of
present day Pakistan and much of Northern India. Their religion is not completely
understood, but appeared to center on fertility with a mother goddess and a horned god
of fertility which resembled a bull. The closeness of this god to Baal, the Mesopotamian
god of rain and the storm, has led some scholars to speculate that there was
trade/interaction between the two societies.

The Vedic
civilization was comprised primarily of the Aryan people who moved into India c. 1500
B.C.E. They were Indo-Europeans, but called themselves Aryan meaning "noble people."
They were not indigenous to India, but apparently originated in the Eurasian steppes and
overspread much of Europe and parts of Asia excluding China, Korea, and areas to the far
East. Whereas the Dravidian people had been primarily agricultural, the Aryans were
primarily shepherds, although they did practice some degree of agriculture. They did not
conquer the Dravidian people, but apparently mingled and eventually absorbed
them.

The name "Vedic Age" derives from the earliest
collection of Aryan sacred writings, known as the Vedas. written in
a sacred language known as Sanskrit. The term "veda" means "wisdom"
or "knowledge." The Vedas has been an important source of information on this time in
Indian history. More detailed information is provided in the links below.