what is the difference between reindeer and deer

Reindeer are a type of deer, specifically the caribou species, that have adapted to the harsh Arctic environment. They are larger than other deer, with a thicker coat of fur and longer legs to help them navigate the snowy terrain. Reindeer are also unique in that they are the only animal that can see ultraviolet light, which helps them spot food sources in the snow. Additionally, reindeer have antlers that can grow up to 5 feet in length, making them the largest antlers of any deer species.