Genre is the word which refers to the categorizing of fiction.
There are many types of genres when it comes to literature, which depend on the style, the theme, the general topics explored in that particular work of literature. So, here are some genres: detective, horror, gothic, romantic, sci-fi, fantasy, etc.
For one, it's best to remain honest even when no ones looking. Secondly, i'm sure the author of what ever it is would like to receive credit for the work they've done. It's just morally & ethically wrong to accept credit for something that's not original work.