Science fictionScience fiction (sometimes shortened to SF or sci-fi) is a genre of speculative fiction, which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, and extraterrestrial life. Science fiction can trace its roots to ancient mythology. It is related to fantasy, horror, and superhero fiction and contains many subgenres. Its exact definition has long been disputed among authors, critics, scholars, and readers.
Speculative fictionSpeculative fiction is an umbrella category of fiction that, in its broadest sense, encompasses all the genres that depart from realism, or imitating ordinary reality, such as in the context of supernatural, futuristic, and other imaginative realms. This catch-all genre thus includes, but is not limited to, science fiction, fantasy, horror, superhero fiction, alternate history, utopian and dystopian fiction, and supernatural fiction, as well as combinations thereof (for example, science fantasy).
Historical fictionHistorical fiction is a literary genre in which the plot takes place in a setting related to the past events, but is fictional. Although the term is commonly used as a synonym for historical fiction literature, it can also be applied to other types of narrative, including theatre, opera, cinema, and television, as well as video games and graphic novels. An essential element of historical fiction is that it is set in the past and pays attention to the manners, social conditions and other details of the depicted period.
Parallel universes in fictionA parallel universe, also known as a alternate universe, parallel world, or alternate reality, is a hypothetical self-contained plane of existence, co-existing with one's own. The sum of all potential parallel universes that constitute reality is often called a "multiverse". While the five terms are generally synonymous and can be used interchangeably in most cases, there is sometimes an additional connotation implied with the term "alternate universe/reality" that implies that the reality is a variant of our own, with some overlap with the similarly named alternate history.
