City of Heroes breaks down Origins of Power into groupings I like, even if they're a bit of an odd fit sometimes.
Natural - Your 'powers' are natural for who and what you are, and any other members of your race or subrace likely have the same powers. Most aliens fit into this, as do those whose 'powers' are merely natural honing of natural ability (-most- martial artists, for example). Superman's abilities aren't because he's superman, but because of his Kryptonian physiology. He's as 'natural' as Shang Chi, Master of Kung Fu. Some people dislike this category because it would also include, say, demonic creatures whose only powers are those found in any other demonic creature from their particular plane of existence. If all demons from Dimension X have super strength and can teleport, then they are 'natural'. Batman most likely fits in this category, though there is some argument about if he should be in Technology. See Technology for more details.
Mutation - Your powers are the result of some significant genetic deviation from the norms of your race. Mutants are the most obvious example of this.
Magic - This denotes individual who derive power from talismans, incantations, curses, or just generally magic. Doctor Strange, Captain Marvel (SHAZAM!), Doctor Fate, the Black Knight, Etrigan (who has more than his 'natural' demonic attributes by way of powers), Merlin, etc. Spawn and The Darkness are also good examples. Swamp Thing is another.
Science - This is for individuals who gain their powers through scientifically derived means, such as Spider-Man or the Fantastic Four. Exposure to strange chemicals, cosmic rays, or through the use of the same (mind control via sprayed on pheremones for example). Captain America is a prime example of the Science Origin. Nova and the Nova Corps fit here as well, as science created and imbues them with the Nova Force. Luke Cage is another example, as is Daredevil.
Technology - This one is a bit tricky as there is some outward overlap with both Natural and Science. The Technology origin refers primarily to individuals whose primary power set(s) derive wholly from technology. Iron Man and War Machine are the poster children of this set, as well as a host of other armored heroes and villains. The Wizard is, if I recall correctly, another as he uses alien technology to mimic the effects of magic. The requirement for classification is that the technology you use drives your identity and origin (Mr. Freeze, for example). As such, individuals like Green Arrow and Hawkeye, who rely primarily on the specific technologies that come with their weapons of choice, often get lumped in here along with Batman, who is Mr. Gadget, basically. The reason Natural is more appropriate for Batman is that Batman's primary weapons (emphasized heavily in his comics over time) are his body and mind, and everything else is just an extension of that. Take away all his gadgets and Batman is still Batman. I'm not sure the same is true for Hawkeye and Green Arrow.