Footnotes - 01: What is "Canon"?

Welcome to the first Footnotes episode of Ravenclaw Readers! We're taking a bit of a break over the festive season, so we sat down for a casual conversation to discuss the idea of "canon". What counts as "canon" in the Harry Potter universe? How should we consider the books, films, Pottermore, etc. in relation to one another? We do come to some sort of a conclusion, but perhaps it is a bit of a "cop-out". This is an ever-evolving topic - so we'd love to hear your thoughts on the subject!