The latter means the option of the two that comes after the first. In this case, Disney World. (Disney World is really epic, far superior to its counterpart in CA if you ask me, so I'm pretty excited to go)
Why don't you people be a simple bunch like us Australians. We have a simple system going from Kindergarten to Yr12.
Ours is simple too. From K-12 we get out from May 18-August 24 and have over 20 snow days with no makeover days. Simple.