A Floppy disk is sealed in a cave.
Data is generally written to floppy disks in sectors (angular blocks) and tracks (concentric rings at a constant radius)
A small notch on the side of the disk identifies that it is writable, detected by a mechanical switch or phototransistor above it; if it is not present, the disk can be written; in the 8-inch disk the notch is covered to enable writing while in the 5-inch disk the notch is open to enable writing

