Wait, is zair when you are about to hit the ground and you press Z at the right time which makes your character roll on the ground instead of hitting the ground?
Nope. That's called a "tech" or "ukemi" (the japanese term). That's an important thing to get good at, so practice
But Zair is just..... well take Toon Link, jump in the air, and hit Z. He shoots out his hook-shot. You can use it as an attack -- it will hit people for damage -- but you can also use it to latch onto the ledge, like if you're just a little past the bottom edge of a main platform of the stage (recovery).
And on the ground the same input (Z, or "Grab" button, or just "Shield + Attack" together) does a Grab: it's an attack that can get people right out of their shield... which is very useful.
Also, Isnt B-Bouncing like Ness's Up+B move? And would Ganondorf's Neutral B move be considered a B-Reversal if he was once standing to the right of the stage when he started his neutral B move and then somehow turned to the left of the stage before releasing the attack?
Ness' up-B is not a b-bouncing anything. B-bouncing is sort of a weird term. Instead first just figure out B-reversals: Use a B move like Squirtle's up-B and just after you press it, tap the control-stick backwards. Squirtle will switch directions with the up-B. Same goes for Falcon Punch, Bowser's Fire, etc. Most B moves can be reversed. Some (like Bowser's fire) cause a noticeable shift in his direction when you reverse it while he's in the air. B-bouncing has to do with this.
Also what type of attack would be considered a meteor Smash?
A meteor smash is when a move sends you straight downwards. Mario's Fair is a good example; if you're in the air and Mario's Fair lands a clean hit on you, you'll be sent straight down. There are quite a few moves that have this property. The "pitfall" item does it too (if you're hit with it while you're in the air).
