Literature can be classified by language, national origin, historical period, genre, and subject matter. Examples of such classification are English-language literature, Japanese literature, Romantic literature, fiction or nonfiction, and war literature, respectively.
Some well-known pieces of literature have been classified into a so-called canon of “great works” that includes such writers as William Shakespeare, Leo Tolstoy, and Gustave Flaubert. Because many of these works were written by white European men, the idea of a literary canon has been controversial, igniting debates about whose voices have been excluded and the standards by which critics and readers assess a piece of writing.