In my world, we don't call it magic. They're simply techniques that anyone can learn, should they be properly trained. Of course, not anyone can master them, and certain shinobi have different techniques that are unique only to them, as our powers largely depend on aspects of our chakra, which is the output of spiritual and physical energy.

When you mold chakra correctly, you can perform a number of different techniques.

[ Kakashi explains all this as he refills his cup of tea then lifts it up. ]

Actually, I've been using a technique this entire time we've been sitting here drinking tea.

[ He takes a sip of tea for emphasis. ]

You see me drinking tea through my mask. But what you're seeing is an illusion, and the technique what we would call genjutsu.