Science Fiction Genre

This site explains what the genre science fiction is. This site says that science fiction are

complete with heroes, distant planets, impossible quests, improbable settings, fantastic places, great dark and shadowy villains, futuristic technology and gizmos, and unknown and inexplicable forces.

The site is pretty good with explaining the genre since it goes on to explain it through examples of movies, and it lists a tons of movies. Each time a movie is listed, an explanation is followed where it explains what made the movie science fiction.