If you and I are in a room together, and I don't want you to walk to the left of me, I pour lava to the left of me.
The end.
While if you hold the bucket of lava I can't go anywhere near you for fear of lava being poured on me...
I have lol'd.I seriously give up.
Ryuu, let's see if I can explain it this way...
* Walling prevents your opponent from getting in onto your character. This way, chances are you'll be spending the time keeping him out of your area instead of aiming for damage.
* Zoning's goal is to wall a specific area so that your opponent stays away from that area. Some forms of zoning leave an 'opening' where your character tries to get to you, when in actuality that opening is a trap that you set for your opponent and when they fall for that trap you can capitalize and increase your lead/take an early stock. The downside here is that while you zone, if your opponent realizes what you're trying to do, you might THINK he's falling for your trap and start up the punishment when the opponent was the one waiting for you to do that so HE could punish YOU!
In conclusion... Walling = mindless defense. Zoning = smart defense.
As for the lava example, what if BunBun had a knife and the building you guys were in was on fire, while he blocked the exit? Would it be better to pour lava on the floor next to him so that you can ONLY approach from the other side, or risk missing by throwing the lava at you and having no plan to stab you easier with?