Science fiction books typically deal with imaginative topics and concepts that focus on science and technology, space, other worlds and universes, computers, robots, and artificial intelligence. Commonly referred to as "Sci-Fi," books in this genre of fiction often take place in the future or an alternate present time.
Unlike most fantasy fiction books, science fiction books are based on science, relying on facts and theories rather than magic or imaginary power. Even though science fiction might use technologies like time travel or intergalactic space travel or take place in a fictional world or different time periods, the scientific elements are plausible, even if they're not true in our reality.