Stories are a result of a sophisticated linguistic system. Typically a story is defined as a recalling  an account of events,  people, things real or imagined, that they have engaged in. 

A book is often the primary way a story is stored and read. image: R.Conan-Davies

Very roughly,  stories can be either fiction or non-fiction. There can be variations in between but if there are imaginary features in the story then it becomes fiction. This often depends on cultural traditions or sensibilities. 

Usually a story is told for the purposes of entertainment , drama, or enjoyment.  This is in contrast to instructions which are primarily for purpose of passing on a specific skill. Although sometimes a story can be used to 'teach a lesson'.

Non-fiction stories form an important part of history. Stories typically have a perspective of some kind and are associated with an author or in some cases a group of authors or editors. This is especially true of news stories.

Stories can be oral (spoken) or written (literature), or presented in range of different ways from television, films, games, dance or even works of art. They can be converted from one form to another and are often the inspiration for one or the other.