Sky is an object that makes the sky section of your choice the picture of your choice. Just like a simple cube, the sky object has 6 sides. Make each side the same picture... or make it look like a room. The default skybox (if no "Sky" object is present in the Lighting) is a blue sky with clouds. The Moon, Sun, and other main sky decals will always be present even if the SkyBox decals differ from the default. The skybox decals are just regular decals that any user can upload. The default decals can be found under the Goodblox textures folder.
The Sky object only incorporates the global functions.
In addition to the Global properties, the Sky also uses these.
The Sky object only incorporates the global events.