Alright guys, whats the difference between these two rather similar structures?
Semantics
Fur is made of hair. For some reason, folks seem compelled (at least in English) to have two words for the same stuff. Off the top of my head, “fur” usually means relatively short and covering the whole animal, and hair means sometimes relatively long, and not necessarily covering the whole animal. So people - even those with short hair - have hair and not fur, although we might describe someone with lots of hair as “furry”. Most mammals we would say are “furry”, but we describe apes as “hairy”, and horses have horsehair, not horsefur. For sheep we have a third word, “wool”, which is also used to describe very curly/kinky people hair in the form “woolly”.
But the stuff is all made of keratin and is pretty much the same thread-like stuff no matter where you get it from. One piece of it is usually called a hair, even if collectively referred to as fur. For instance, my dog has fur, but he leaves dog hair on the counch and there’s a dog hair in my coffe cup.
As I understand it, fur falls out at a certain length. Once the fur gets to a certain length, is falls out. This keeps the fur short.
Hair, on the other hand, does not stop growing. (Except for that whole Male Pattern Baldness thing).
Humans are covered in fur. The only hair is found on the head.
Human head hair stops growing eventually and falls out too; it just grows longer than the hair/fur on the rest of our bodies. Check out the "Does shaving make hair grow faster? " post from the 2nd (haven’t figured out how to make links yet) for more on that. As for the difference between hair and fur, it may just be in the structure and function… I’ve read that gorillas for example have a layer of short curly “fur” underneath their long black “hair” that covers their bodies. I’m somewhat stumped for anything further.