Theme (narrative)

Theme in writing is what you think is important in a story. It is the big idea of the work. 
In contemporary literary studies, a theme is how the central topic a text, book, or story is treated. Themes can be divided into two categories: a work's "thematic concept" is what readers "think the work is about" and its "thematic statement" being "what the work says about the subject".
The most common understanding of theme is an idea or point that is central to a story. It can be summed in a single word (e.g. love, death, betrayal). Some examples of themes of this type are conflict between the person and society; getting to adult age; humans in conflict with technology; nostalgia.
A theme may be shown by the actions, words said, or thoughts of a character in a novel. An example of this would be the theme loneliness in John Steinbeck's "Of Mice and Men". Many of the characters are lonely. It may be different from the book's or author's view of the world. From the source we found we can see that the themes can be at a variety of state as the worldwide web