Science fiction: Hard core science fiction mostly set in the near future. The fiction consists of one (or a few) scientific breakthroughs and postulating how it affects today's mankind. This genre is dominated by short stories.
Science fantasy: How it will be in the far far future. Characters and plot are more important. The scope is larger. Philosophy and social science in this future world play a large part. Scientific breakthroughs are numerous and in all areas (but not totally unbelievable, consistency is key).
Space Opera: Pirates with phasers. Characters have a central stage, sadly they are often larger than life, and become caricatures. The plot spans the whole galaxy and all its cultures. Science is magic, convenient for the story and generally unbelievable.
Slashdot Mirror
I hope you mean the book, the film sucked. Carl Sagan would be appalled by it.
My science fiction subgenres in short:
Science fiction: Hard core science fiction mostly set in the near future. The fiction consists of one (or a few) scientific breakthroughs and postulating how it affects today's mankind. This genre is dominated by short stories.
Science fantasy: How it will be in the far far future. Characters and plot are more important. The scope is larger. Philosophy and social science in this future world play a large part. Scientific breakthroughs are numerous and in all areas (but not totally unbelievable, consistency is key).
Space Opera: Pirates with phasers. Characters have a central stage, sadly they are often larger than life, and become caricatures. The plot spans the whole galaxy and all its cultures. Science is magic, convenient for the story and generally unbelievable.
-- Less is more!