About retrocomputing, I have a lot of experience with MS-DOS and the earlier version of Microsoft Windows (together with tons of other software). You can contact me at email@example.com
Examples of the use of the asterisk under MS-DOS:
Delete all files that start with x and have a .BIN extension:
Delete all files in a directory:
Show me all the folders, but without showing me the files:
Because the asterisk means any file with any name and, since after the 'dot' I didn't write anything, it means that the 'items' to show must have no extension at all. Folders did not have any extension, so that command showed all folders but not files, because all files had some sort of extension.