Things that are hereditary are inherited — passed down through the DNA of your biological parents.
Has anyone ever said "You have your mom's eyes" or "Wow, you look like your grandfather"? They're commenting on hereditary features — things you got from your parents, and their parents, and all the other family genes you carry. Hair color, height, and even parts of your personality tend to be hereditary, or passed down genetically. Not all hereditary things are good: you can also inherit health conditions, crooked teeth, or your grandpa's bald spot.