Fiction and Fantasy are two words that might sound closely related based on your earlier knowledge of the two words, but they are not totally the same. Although both terms explain things that are not real, in fact, they are things that will come through your imagination. First of all, fiction is a literary type using invented or imaginative writing, without using real fact. The concept of aliens is mostly discussed using fiction. Also, fiction can be used to discuss inventions that are not yet real.
Fiction is mostly used to explain the possible technological advancements which are more liable to occur in some years to come. Although they are not real the possibility of them coming true can still be substantiated with already existing facts. Fantasy, on the other hand, literally means something that comes from one's imaginations. It is also a literary type which deals with themes of magic and technologies of the middle age. For example, the concept of wizards, dragon, and other magical beings are mostly discussed through Fantasy.