Fanon

Fanon is an unconfirmed belief held by fans of a series. Such beliefs may be based in canon (the things that have been confirmed), or they may not be.

For instance, it is canon that Delia Ketchum is Ash's mother. This is said in no uncertain terms. However, any conjecture of Ash's father is purely fandom, as the only mention of such a man in canon is how long it took him to get to Viridian City, and that he is supposedly a great trainer.