Well done, Lyra. Well done.

makes much more sense than 50% of every other head cannon out there…

The difference is fur grows in coats of more than one hair, and at least two types of hair, per follicle. An otter has one guard hair and around a hundred undercoat hairs per follicle. Porcupines have three types: quills, guard hairs, and undercoat.
 
Technically, horses have hair, not fur. However, “Equestria Girls” (the official promo song/video from a couple years back, not the recent movie) stated they had “furry coats” in addition to being “so cute [they’ll] blow your minds.” Therefore, MLP:FiM ponies might have fur.

… the definition you just gave for “fur” just called it “soft hair”.
 
Just saying.

@Background Pony  
Hair is an outgrowth of protein, found only on mammals. The primary growth of hair fiber is keratin; keratins are proteins, i.e., polymers of amino acids. It projects from the epidermis, though it grows from hair follicles deep in the dermis.  
The term fur refers to the body hair of non-human mammals also known as the pelage (like the term plumage in birds). Animals without fur may be referred to as “hairless” or “naked.” At certain stages of life, hair is absent in some of the species.
 
 
Fur: The thick coat of soft hair covering the skin of a non-human mammals, such as a fox or beaver.  
Tends to grow in more synchronized manner and stops at a certain length.  
Includes double composition.  
Coarse, short  
Hair: A growth of such filaments, as that forming the coat of a human.  
Tends to grow independently and does not stop growing.  
Single composition or texture.  
Soft, can be long.
 
So yeah, there’s a difference.
 
Horses have a coat of hair. Deal with it.

@Background Pony  
… PFFT SURE OKAY.

@Background Pony  
Just to be clear, there is no difference between fur and hair… At all.

Headcanon accepted.

Horses don’t have fur, it’s a coat of hair.
 
http://equestrianoutreach.com/Equestrian-Outreach-Equestrian-Information-Page.html

Then why isn’t her tail brown?

@HJSDGCE  
Just like a hippie

Wow…  
She must smell.  
No wonder she lives outside of Ponyville.