Recently I've seen a few slide decks on Entity Framework's architecture that have made me cringe.
Their crime: mislabeling an EDMX file as EDM.
Now without doubt, you have to be a hard core metadata freak like me to find this offensive.
But take my word for it that X is super important, for without it the wrong message it sent.
My point is this: The Entity Data Model or EDM has nothing to do with storage models or model to model mapping, it simply describes the conceptual model.
An EDMX file on the other hand has all three: conceptual model, storage model and mapping:
Now we at Microsoft must shoulder the blame for perpetuating this misunderstanding, we've been a bit wishy-washy in our documentation on this, and then to top it all off we called the file that groups the conceptual model, storage model and mapping together an EDMX file, when that extension does imply that it is simply the EDM (in) X(ml) format.
Anyway I hope my passion for something so trivial has helped get my point across:
The EDM is just a conceptual model, nothing more and nothing less.