The story of every game of The Legend of Zelda is pretty much the same: Evil monster king tries to claim a godlike wish-granting artifact, the Triforce, in order to dominate the world, and a sword-wielding fairy child and magical princess team up to stop him. There are 27 Zelda games at this point, and the vast majority are remixes of that basic idea in some form or another. And for years, that's all it seemed like the Zelda games were: different takes on the same idea, the same game revisited with interesting tweaks along the way.
With the release of The Legend of Zelda: Skyward Sword, though, Nintendo did a lot to recontextualize the Zelda series. Chronologically, the game is the "first" Zelda title--it marks the beginning of the series, the very first time a monster king was defeated by a sword kid and a magic princess. Casual Zelda fans might not have really thought about it, but that creates some pretty huge implications for the world the Zelda games take place in. It means that each of the adventures in the Zelda series aren't just different takes on the same apocalyptic monster-king war: They're all separate, uniquely horrific apocalyptic monster-king wars.