Because I love contrasting terms, I think I’m going to summarize two more of them! It really does help me to remember the terms (there’s a LOT of them in our readings) if I write them down in my own words and try to find examples for them.
At first glance, “intra” seems to indicate something internal, whereas “extra” represents something external. Finally, “diegetic” is a type of storytelling, specificially the act of describing things (rather than showing them).
Both terms are considered opposite “diegetic levels” – or levels of involvement in the story (that’s how I understood it, at least). I noticed that most examples of “intradiegetic” and “extradiegetic” involve the narrator specifically – his / her involvement in the story.
An intradiegetic narrator is one that is inside (intra) the narrative (diegetic). This narrator may be represented by a character, telling his story from the first-person perspective (for example, Huckleberry Finn). You may even have a narrator (as seen in the Great Gatsby) who tells the story of someone else. Or, from one of my all-time favorite examples, Dandelion narrates the Witcher and also shows up as a character in the game. As long as the narrator exists in the story, he is an intradiegetic narrator. Similarly, anything inside the story is considered to take place on an intradiegetic diagetic level.
Many traditional novels are also narrated from the extradiegetic diagetic level. It’s the opposite of our last term: the narrator exists outside (extra) the diegesis (events described by the story). An easy example of this is the Harry Potter series, which has a third-person omniscient narrator. There are a lot of examples of this, though: think of virtually any narrative that has a narrator that doesn’t represent a character in the story.