For your edification, the most common form factor of floppy disks:
5ΒΌ inch (no metal door thing)
3Β½ inch (the one the save icon was modeled after)
There were also 8 inch (used before 1980s mainly), and various not very successful 3 inch, 2Β½ inch and 2 inch formats.
Note that while the form factor might have been the same, a lot of diskettes aren't mutually software compatible between systems.
There's physical sub-formats (e.g. one sided, hard sectors, varying supported densities due to magnetic properties etc.) too.
