I went to Tranquillien for some story inspiration, but all of the blood elves there seem even more catty than usual. Are they bitter for being banished to the Ghostlands? Or were they the winners in some catty contest? I just don't care.
Canon refers to the actual events and characters that exist in a fictional world. Headcanon refers to any situations or characters that are imagined by fans of said fictional world. Sometimes they are silly, like the fact that Garrosh's favorite treat is lemon squares. Sometimes they are serious, like positing that tauren store grief in the lungs. For my writing, I've come up with a lot of headcanon. Got a theory about a torrid romance between your favorite auctioneer and the patrolling guard? Given any thought to where mounts and pets go when they aren't summoned? Do you know how your characters do their laundry, or what Baine Bloodhoof does in his free time? What are your headcanons, and where did you get the idea?
So I went to Brill.