MFS is notable both for introducing resource forks to allow storage of structured data, and for storing metadata needed to support the graphical user interface of the classic Mac OS.
Folders exist as a concept on the original MFS-based Macintosh, but work completely differently from the way they do on modern systems.
To display the contents of a particular folder, MFS scans the directory for all files in that handle.
[citation needed] While this is small by today's standards, at the time it seemed very expansive when compared to the Macintosh's 400 KB floppy drive.
In Mac OS 7.6.1, Apple removed support for writing to MFS volumes “as such writes often resulted in errors or system hangs”,[3] and in Mac OS 8.0 support for MFS volumes was removed altogether.