Science fiction is often unfairly compared with fantasy books for educational uses. This is a weak analogy because the two genres are so very different. The two are only related in that they both fall under a larger genre known as speculative fiction and are found in the same section in bookstores.
Science fiction, also known as SF or sci-fi, is part of a larger genre within fiction known as speculative fiction. Speculative fiction not only includes science fiction, but also fantasy and horror as well.
This is a three-part article written by Jim Marrs, the author of the New York Times bestseller “Alien Agenda.” Part 1: A History of Alien Invasion Stories. Some believe the battle for Earth has already begun.
The idea of space travel—which is central to the plot of L. Ron Hubbard’s epic SF novel Battlefield Earth (1982)—has been written about in science fiction for hundreds of years. Sci-Fi writer Jack Williamson called space travel “the central myth of science fiction,” just as the fall of Troy was the central myth of the ancient Greeks.