Nonfiction - again- is real. The facts cannot be made up in your head, they have to be real. Such as if you're writing a research report on keeping dogs healthy, you don't wan't to put false information. That can eventually lead to serious situations, depending on what you writing.
Differences between Fiction and Nonfiction
As the graph shows above, these are the differences between fiction and nonfiction. Make sure you don't get the two confused the next time you're looking for a book or writing a paper.