[Groxx]

Along somewhat similar lines, my main division between the two is that sci-fi generally touches on the interaction between "people" (often the main characters, but not usually limited to them) and the world's systems (politics, war, how future tech changes society, etc), while fantasy generally focuses on individual's internal struggles (how they deal with the violence in their swords and magic world, how they get along with their squad, how they deal with the politics they're stuck in).

Which isn't to say one is more personal than the other, just that the focus is different. How the world as a whole handles something can easily be covered with a single character's thoughts, and they can be worried about how they interact with the world that surrounds them.

No division is perfect of course, but I think it fits pretty well with a lot of the genre-bending works, and better predicts who will like what book. Some are totally in X genre because of the setting itself, but more often I find people sticking to one or the other because they like that kind of story.

(Also Le Guin is fantastic, very obviously an exceptional author, and you should absolutely read some of her works)