Science Fiction (Sci Fi) is a broad genre that deals with science and technology either in a present or future tense, or even a different dimension.
Science fiction differs from other forms of fiction in that a large amount of the imaginary elements of a story are theoretically possible within our current understanding of the laws of physics. A number of stories feature possibilities with these laws that are either unlikely or largely unknown.
Science fiction has been developed since the birth of science itself, and could be considered to have grown from those first few people who were willing to look beyond their own limited knowledge and understanding of the world and to dream of what may be.
In the early 20th century, science fiction began to gain popularity with the publication of magazines written largely by americans dreaming of space. The most popular of the magazines of this time was Amazing Stories, also called Amazing Science Fiction and featured stories from the great early authors like HG wells, Jules Verne and Edgar Allen Poe. The publications acted as a catalyst for new talented science fiction writers like Isaac Asimov, Damon Knight Arthur C clarke and Robert A heinlein.
It is no coincidence that most of these names are still known and their novels still read as the rise of these authors was considered by many to be the birth of a golden age of Science Fiction.
Since that time, science fiction has continued to develop and evolve and at many time has reached a mainstream audience, due in part to movies like Star Wars, Alien, and 2001. And television series like Star Trek, Babylon 5 and Doctor Who.