https://en.wikipedia.org/wiki/Metafiction
a form of literature that emphasizes its own constructedness in a way that continually reminds the reader to be aware that they are reading or viewing a fictional work. Metafiction is self-conscious about language, literary form, storytelling, and directly or indirectly draw attention to their status as artefacts. Metafiction is frequently used as a form of parody or a tool to undermine literary conventions and explore the relationship between literature and reality, life, and art.
Although metafiction is most commonly associated with postmodern literature, its use can be traced back to much earlier works of fiction.
https://en.wikipedia.org/wiki/Postmodern_literature
2Common themes and techniques
