system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel/DC]What distinction is there between magic and other superpowers?

Examples: Thor controls the storms. He's magic. Storm is even more versatile, but she's just a mutant. 

Magik, Colossus' sister, is a mutant who can open portals to limbo, among other things, and is considered a sorceress. Nightcrawler teleports himself through Hell on a regular basis, but he's just a mutant. 

Scarlet Witch is a mutant who is magic. Phoenix is a cosmic entity often bound to a mutant. 

Cyttorak is a cosmic entity who is magic, thus Juggernaut's powers are also magic. Galactus is a cosmic entity but is not considered magic, thus Silver Surfer's powers are "cosmic". 

I could go on, and you guys could probably come up with ten times more examples still (and I didn't even mention DC properties). How do their universes distinguish between which powers are magic versus which are mutations, cosmic, alien biology, lab accidents, etc., beyond just the writers declaring, "he's magic" or "she isn't"?
gpt
Mutants and mutates are born with their powers or develop them naturally in response to a stimulus. It's an innate ability. Also, many superheroes in this category are non-human and their powers are just normal for their race.

Magic is learned or bestowed (although you might have been born with an affinity or talent for it), which makes it a skill instead of a trait. Magic also tends to be a bit more fiddly about its rules and limits.

> Scarlet Witch is a mutant who is magic.

Yes, she's both. Her mutant power is reality warping by altering probabilities. That power also gives her an intuitive grasp of magic, which she was taught (among other things, it varies from universe to universe).