"Humans" and "Deimos" refer to the 'main' characters- in other words, characters you can actually play as. Other refers to minor characters, bad guys, and NPCs.

In case you couldn't guess, there will be spoilers abound in the profiles. If you haven't played through the game or have no idea whatsoever of the basic plot, you'd be best off not reading these. (No complaining about spoilers, now!)