In the Screenshot above you can see both: I changed to the Folder Applications and after I tried to change to Folder Programme, this folder does not exist.
Here the Folder Applications does not exist cause of the translation. Bit in Finder by self you will see again: Applications and not the translated Programme
So the sidebar shows Programme instead of Applications but the rest shows: Applications. Means: only the Sidebar is translated, the rest not. So the Folder Structure is still like it shall be and nothing is redirected.
Next, three localized items:
Bibliothèque
Système
Utilisateurs
NB: Applications exists in French (but it could have been translated to Programme, but prudence tells the localization people to translate the less possible OS things).
Next: the ListBox Header tells what it is (external SSD):
The pink entry without name: I do not know what it is (0KB, created/modified on… 1904-01-01 00:00:00); this is a file.
At last, a folder with a Custom Icon:
That SSD is shared alternatively on an Intel i5 MBP, then MBP m1. So, sometimes that invisible file who holds a Return character at the end of the file name is replaced with a ? character (yes, the question mark as seen above). It is invisible in the Intel Finder, and visible on the m1 Finder (and I do not kow why).
The .DS_Store file is created when a folder is opened for the first time (and then modified by the Finder if/when needed). A folder that was never opened will not have one.
The actual folder names are internally always in English, and that’s what is visible in the Terminal.
As Christian said, Finder translates them on the fly, so that the user sees the localized names. It happens only for a selection of hardcoded localized folders (Applications, Users, Documents, Library and so on) when there is an empty “.localized” file present in the folder. If you remove the .localized file, the localized name will no longer appear.
You may also localize any custom folder. To do so, just create a folder with .localized extension (for example, “My Folder.localized”), create a “.localized” folder inside, and then place a text file there with the desired language code name and .strings extension (de.strings for Deutsch, pl.strings for Polish, fr.strings for French etc., one for each language) containing the original to localized name mapping, such as:
"My Folder" = "Mon dossier";
Don’t forget the semicolon! Reboot (forcing the Finder to quit should be also enough) and enjoy your localized folder names.
It might be useful when preparing localized versions of your software.