Natural or supernatural?

I was watching a fantasy movie, enjoying the tale of wizards and magic, with fantastic animals and creatures. Later I was wondering what magic can actually be? It is clear to me that there is no scientific evidence about magic, but if magic were true, then what exactly would it be?

Agent of wishing

As usual during the lunchtime someone wished “Bon Appétit!”. We all said thank you and started. I suddenly thought, but wait, thank you for what? what does it exactly mean to actually wish someone something? How do I make sure if my good wish is actually granted to the receiver? Isn’t wishing not an empty endeavor anyway?