Who were the Indo-Europeans? How do the steppes relate to the Indo-Europeans?
The Indo-Europeans were a group of nomads who may have come from the steppes—dry grasslands that stretched north of the Caucasus mountains, between the Black and Caspian seas.
What is migration? Do we know why the Indo-Europeans migrated? How long did it take?
Migration is a group of people moving from one place to another. Although we don't know why the Indo-Europeans migrated, we do know that it took a very long time.