On Windows, you can’t have a file named file and another file named FILE in the same folder. The Windows file system isn’t case sensitive, so it treats these names as the same file.
On Linux, the file system is case sensitive. This means that you could have files named file, File, and FILE in the same folder. Each file would have different contents – Linux treats capitalized letters and lower-case letters as different characters.
This means that the wierd looking files are files that windows could handle.