difference between extensions and userpatches/extensions directory

[leggewie]

"Extensions live in extensions/ or userpatches/extensions/ directory"

Kindly explain the role of each directory and when an extension ought to be placed in one or the other. Am I correct to think (after looking at .gitignore) that userpatches only live on the local dev's machine and extensions/ are published as part of the Armbian project but not part of core?

[igorpecovnik]

userpatches only live on the local dev's machine and extensions/ are published as part of the Armbian project but not part of core?

yes. build FW will also look for extension there.

[EvilOlaf]

My first thought was explain difference directly there but then I realized it wouldn't make much sense since this explanation would be out of scope for the extension topic.
I think at some place are (or better should) the directory structure be explained and then simply link there.