Genre

dictionary definition:
a class or category of artistic endeavor having a particular form, content, technique, or the like - Dictionary.com

my definition:
A particular category a peice of literature falls into.

example:
The Legends of Cryptozoology are often in the fiction genre.

how it relates to __The Boy in the Striped Pajamas:__

 * __The Boy in the Striped Pajamas__** would be in the genre of historical fiction. Its based on facts but the characters were never real.