"Can anyone help me to understand the meaning? "
When you look at those files then they are shown with lots of lines. You might even think that text files are saved somehow in "lines". But all text files are in fact just saved as one long vector of characters. Within that long vector of characters the "end of line" (aka EOL) characters are special characters** which tell your text editor that "this is the end of the line, please start a new line".
But different operating systems use different EOL character/s:
The files you uploaded contains exactly the same printing characters, but use different EOL characters.
So in most text editors they will look the same, unless you turn on the feature to show all characters:
We can clearly see in the above screenshots the EOL characters:
- zone - Kopie.txt uses only LF (linefeed), used by Linux, macOS, etc.
- zone__ - Kopie.txt uses both CR and LF (carriage return and linefeed), used by Windows, OS/2, etc.
But... badly written applications which assume particular EOL characters might fail to work with one/both of those files. If the application requires particular EOL characters, then you will have to change the file/s to suit that application. Any reliable text editor offers this feature, e.g.:
Edit -> EOL Conversion
** The EOL characters are also non-printing characters (i.e. you cannot see them), but otherwise they are just perfectly normal characters. By the way, there are also many other non-printing characters or control characters: