Genre fiction can be confusing, especially given the plethora of sub-genres. Here are some handy definitions, for the next time you find yourself out of your depth when contributing to the conversation about science fiction.

science fiction we can’t solve problems in the real world, so let’s invent a world and fail to solve its problems

space opera the universe is a very dangerous place… especially when human beings are around

military science fiction war is bad, and we shall demonstrate this by glorying in it

planetary romance slavery is okay if their skins are a different colour, like green

hard science fiction science and technology can be dehumanising, so we will replace everybody with computers and robots

cyberpunk corporations with the power of life or death over individuals are bad, so I shall take all that power for myself

alternate history if science fiction didn’t exist, someone would have had to invent it

steampunk the Victorian era was repressive, racist, sexist and imperialist, but at least they had giant airships

science fantasy any sufficiently advanced technology is indistinguishable from authorial wish-fulfilment

And it’s a subgenre of fantasy, but…

urban fantasy vampires are a metaphor for sexual predation, so we will make it all about sex