Science fiction is, as the name implies, a genre that merges scientific theory and accuracy with fictional stories. People often use the term to describe so-called "hard sci-fi" and "soft sci-fi" interchangeably. Hard sci-fi focuses more on grounding the story with scientific realism, while soft sci-fi worries less about scientific accuracy and generally has many more fantastical elements.

One thing you should keep in mind about hard and soft science fiction is that these aren't rigorous definitions. Each is one end of a broad spectrum, with most works of science fiction falling somewhere in between. Most of the science fiction you read or watch will have elements of realism alongside fantastical inventions, but will probably trend toward one end of the spectrum or the other.

In Chapter 5, we focus on the more traditional definition of science fiction as fiction grounded (mostly) in science, while Chapter 6 looks at the other end of the spectrum (which we call "space opera").