Retroactive continuity

Retroactive continuity (or retcon) is when changes are made to a story after it was first published or released. This means new information or events might be added or old information or events might be changed. It's like if you're telling a story and you change something that happened at the beginning after you've gone further in the story. Retcon is used in books, movies, and comics to make changes over time without having to start from the beginning.