Science fiction is a genre of fiction with imaginative content such as settings in the future, futuristic science and technology, space travel, parallel universes,aliens, and paranormal abilities. Exploring the consequences of scientific innovations is one purpose of science fiction, making it a “literature of ideas”. Science fiction has been used by authors as a device to discuss philosophical ideas such as identity, desire, morality, and social structure. Science fiction is largely based on writing rationally about alternative possible worlds or futures. It is similar to, but differs from fantasy in that, within the context of the story, its imaginary elements are largely possible within scientifically established or scientifically postulated laws of nature.The settings for science fiction are often contrary to consensus reality, but most science fiction relies on a considerable degree of suspension of disbelief, which is facilitated in the reader’s mind by potential scientific explanations or solutions to various fictional elements.