Huckleberries need to be foraged, whereas blueberries can be farmed. In the wild, huckleberries spread out on branches while blueberries cluster together near the ground.
On the inside, huckleberries are a bluish-purple color and have large, tough seeds, but blueberries appear a greenish white and have soft, little seeds.
Huckleberries range from tart to sweet, while blueberries are almost always pretty sugary. Confusingly, though, the term "huckleberry" is sometimes used to refer to blueberries.