The Finder tries to display file names using localized text. For example, the name of the Desktop folder is always "Desktop". But in French, it would read "Bureau". But internally, programmers rarely have to worry about those details, they can simply refer to "Desktop" and they know it will always work.
However, if you start poking around in hidden folders like "Mobile Documents", you are going to see some strange side effects in the Finder. That's all that it. If you look at that folder using the UNIX Terminal, then you will see all of the real file names and they are all unique. They are also probably all in plain ASCII characters. But this folder isn't design to be directly viewed in the Finder, so you'll see strange things if you navigate there on purpose. If you use the "iCloud Drive" folder, you will see a better representation of how this information is supposed to be displayed.
There are several places in the operating system where what you see in the Finder, or on the Desktop, isn't an accurate reflection of reality. I recommend not looking too deeply.