Large hoofed animals belonging to the deer family, caribou and reindeer are actually the same species—Rangifer tarandus. There are differences between caribou and reindeer though. Caribou are native to North America, whereas reindeer are native to northern Europe and Asia. Alaska does have some reindeer, however, imported from Siberia in the late 19th and early 20th centuries.
(What color are reindeer eyes? Depends on the season.)
Some people use the term "reindeer" to refer to domesticated work animals, such as those pulling Santa's sleigh, but there are both wild and domestic herds of reindeer. Caribou, on the other hand, live in the wild and take on long annual migrations. Indigenous groups, including the Sami in northern Scandinavia