Sci-fi or fantasy is a GENRE of fiction that typically involves elements of science fiction, fantasy, horror, supernatural, and other imaginative themes. It often features futuristic settings, advanced technology, and otherworldly creatures. Sci-fi or fantasy stories often explore the potential consequences of scientific and other innovations, and can be set in alternate universes or on distant planets. The GENRE has been popular for decades, with classic works such as J.R.R. Tolkien's The Lord of the Rings and H.G. Wells' The War of the Worlds.