Sci-fi, or science fiction, is a GENRE of speculative fiction that typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, and extraterrestrial life. It often explores the potential consequences of scientific, social, and technological innovations. Sci-fi has been around for centuries, but it was popularized in the 20th century, particularly after World War II. It has since become a staple of modern culture, inspiring films, television shows, books, video games, and more.