I know it does, it was me who explained that mechanism elsewhere in the thread.

I was responding to smouty who in answering the question of why the Mac treats AVCHD differently to Windows said, "It a container" as is if that explains why it appears on the Mac as a Package.

But the AVCHD folder isn't inherently anything other than just another folder with files in it. Which is how it would appear on other OSes.

And it is certainly very different to the MP4 container, which is a single file and seen that way on all OSes.

It is only because macOS has some specific code in it to detect that the folder is special and present it to the user as a Package.

But I guess it all comes down to what we mean by "a container" 😉

As an aside, I'm curious to know what heuristics macOS uses to decide a folder is AVCHD. I can see that just changing the extension on a folder to .AVCHD triggers it to identify the folder as an "AVCHD Collection"

But the real AVCHD folder isn't going to have that extension and would likely be on a FAT filesystem so would not have extended file metadata to give a media type.

Just calling a folder AVCHD doesn't trigger it, so I assume macOS must look in the folder for the folders/file types expected in AVCHD to determine it.

Though to add further confusion to the terms, Apple also calls them AVCHD Collections in the media type...

In reply to a post by andynormancx:

Though to add further confusion to the terms, Apple also calls them AVCHD Collections in the media type...

Helpful... at least not new for an industry where every manufacturer thinks they are the only ones in the industry!

In reply to a post by jchamier:

Helpful... at least not new for an industry where every manufacturer thinks they are the only ones in the industry!

So confusing, but now I know I can cope with it. Very interesting, thanks peeps.