Literature, in its broadest sense, is any written work; etymologically the term derives from Latin literatura/litteratura “writing formed with letters”, although some definitions include spoken or sung texts. More restrictively, it is writing that possesses literary merit, and language that foregrounds literariness, as opposed to ordinary language. Literature can be classified according to whether it is fiction or non-fiction and whether it is poetry or prose; it can be further distinguished according to major forms such as the novel, short story or drama; and works are often categorised according to historical periods or their adherence to certain aesthetic features or expectations (genre). Taken to mean only written works, literature was first produced by some of the world’s earliest civilizations—those of Ancient Egypt and Sumeria—as early as the 4th millennium BC; taken to include spoken or sung texts, it originated even earlier, and some of the first written works may have been based on an already-existing oral tradition. As urban cultures and societies developed, there was a proliferation in the forms of literature. Developments in print technology allowed for literature to be distributed and experienced on an unprecedented scale, which has culminated in the twenty-first century in electronic literature.