Well, the theory of the timeline is crazy, involving multiple timelines diverging at the end of Ocarina when Zelda sends old link back to be a kid, thereby creating two universes, one with young Link and Zelda fighting Gannon, and another with Link and Gannon no longer existing. This much is confirmed. But a lot of it is up for grabs.
This video explains it very well. I suggest it. However a lot of stuff here is not absolute, and I disagree on certain points with their timeline.