Sky

The Sky is where Skyloft and many other floating islands are located in Skyward Sword. It is also where the game indirectly begins.

History
Before the events of Skyward Sword, a large horde of monsters led by Demise appeared from beneath the ground of The Surface world, and began leading a massacre against the people of the surface. The monsters wanted only one thing, the ultimate power given to Hylia by the gods of old. To prevent the great power from falling into the hands of the demonic creatures, Her Grace gathered all the remaining humans on a plot of land and brought it up skyward. Centuries later, the civilization living above the clouds is living a peaceful life, with the protection of the Statue of the Goddess decipting Hylia, presiding over them. The Statue of the Goddess was built so that Hylia, could keep the Goddess Sword, Fi, and the Triforce hidden away from the mortals, and to keep them safe for the choosen hero of the goddess. The technology of the region has also greatly advanced since Skyloft was risen into the heavens, even surpassing The Surface's technology, with windmills that have the power to raise the sacred Light Tower, Beetle's Airship, and various lighting and furnishing. However, the Skyloftian's are known for the way that they travel around the islands of The Sky, on large shoebill-like birds called Loftwings, who are mostly tamed and ridden on by the students of the Knight Academy. The economy of The Sky is mostly based upon the various minigames located above the clouds, the famous pumpkin pub; the Lumpy Pumpkin, and the Bazaar and Fun Fun Island.

There are numerous islands in which Link is able to travel to with the help of his Loftwing, earning treasures and Heart Containers after locating the corresponding Goddess Cube from the surface. Also located in the sky is the Thunderhead, where the great spirit of the skies, Levias, resides, as well as the main location of the Isle of Songs.

Link is not able to travel through the sky at nighttime, as he is not a graduated knight from the Knight Academy. The only way in which he is able to explore a single island outside of Skyloft if Beedle's Island when he falls asleep inside the aircraft.

Goddess Cubes
Goddess Cubes are mysterious cubes spread onto the world by the Goddess Hylia in order to assist her chosen hero. When Link uses the Skyward Strike on these cubes, it disappears from The Surface and beams into the sky, unlocking a Goddess Chest.