Fantasy
Considering the fact that the characters in The Raven Boys are going on a quest to seek out magical energy lines and the buried body of a Welsh king (who's still alive because he's magical), it's safe to say that this book fits squarely in the fantasy category. Blue, Gansey, and the other raven boys encounter all sorts of supernatural phenomena as they explore Henrietta, Virginia. From talking trees to fish that appear out of nowhere to cavernous tree trunks that impart strange visions… there's no shortage of the fantastical in The Raven Boys.
Quest
From the beginning, it's clear that Gansey is on a quest to find Glendower, and he will stop at nothing to reach his goal. But the story isn't just about Gansey's quest; the other characters are on their own personal journeys as well. Blue's on a journey to find her own magical powers, Adam's on a journey to become his own man, and Barrington Whelk is on a journey to harness all the power and wealth in the world. All these personal quests bring these characters into contact with each other, for better or for worse.
Young Adult Literature
The Raven Boys may deal with some pretty dark themes—like death, murder, and suicide—but it's undeniably written for a teen audience. The characters are all teenagers, and though their problems are pretty intense, they're also relatable to the average young adult. After all, lots of teenagers can relate to Adam's family problems, Blue's struggles to obey her mother, and Gansey's desire to not end up just like his dad. And even though Ronan is super messed up, you can still relate to his impatience to grow up and live his own life, free of his brother's influence.