also "sci-fi" (skiffy) if you're afraid of using too many syllables.
a genre of fiction, consisting of stories that, broadly speaking, dare to imagine new inventions, technologies, or scientific discoveries, and how they would affect the world. often this will consist of showing us how humanity would use these new discoveries to destroy itself or oppress each other; there are startlingly few stories where police using psychics to stop crime, or society having a robot taskforce, or people upgrading themselves with cyborg limbs, actually turns out to be a *good* thing (though this may just be because stories where only good things happen are boring).
some concepts you should know about so you won't look like a dweeb in front of sci-fi fans:
* the future, where a lot of these stories tend to take place
* aliens, folks who come from off this island earth. show up in a lot of sci-fi stories, usually invading us, getting invaded by us, or just sort of hanging around bars as a way for the special effects team to show off.
* robot, artificially constructed people, because naturally you'd want your smartphone to look like a person
* ftl: faster-than-light travel, required in any sci-fi story with space travel, or else it would take millennia to finish
* time travel: being able to leave today and go to yesterday, or tomorrow. prone to logical paradoxes.
* hard science fiction: sci-fi that tries to be as realistic as possible. is not a form of pornography
* space opera: stories where people fly around in spaceships and have fantastic adventures on other planets
* cyberpunk and other punk; stories that show how technological process won't fix society's usual problems