Reindeer or Caribou?

We've all always wondered--what is the difference in a caribou, like these cooling off on a chunk of ice in Denali National Park, and a reindeer. Here are reindeer enjoying life at our Wasilla home, the Agate Inn. (If you come to W. stay here. It's great.)

And the difference? Caribou are wild; reindeer are domesticated (kind of). So a caribou can turn into a reindeer.