[Middle English, from Late Latin, from Latin, standard] a : an authoritative list of books accepted as Holy Scripture b : the authentic works of a writer c : a sanctioned or accepted group or body of related works
Lore is an incredibly huge part of the Warcraft universe. It tells us where the world has been and can give us clues about where it will be going. Unfortunately, it can become very muddied as more and more people contribute. When I was in high school, I can remember reading many of the Star Wars novels, which took place in the "expanded universe." The names and places were often the same, but there were often glaring inconsistencies from author to author. When you grow up with a universe, as I did with Star Wars, or when it grows up with you, those inconsistencies can drive you nuts.
The difference that you find in the much of the licensed material that comes out about the Warcraft universe is that Blizzard has a much stricter control over what can be created. Blizzard works with the authors and artists and will often give them advance knowledge of where the property is going, story-wise, in order to make the work fit with unreleased game content. The first time I noticed a character from a licensed product in game was when I stumbled upon Dar'Khan Drathir in Deatholme while leveling my first blood elf. The first book of the Sunwell Trilogy was published almost two years before The Burning Crusade went live. As we progressed into and through The Burning Crusade and Wrath of the Lich King, more characters from the books, manga and comic worked their way into the game.