Densities are an issue only when using older computers that have double density disk drives. High density disk drives will read and use any density disk. However, computers sold before about 1990 often had double density disk drives and these cannot read high density diskettes. Top of Page Diskettes rotate within their permanent jacket at either 300 or 600rpm. The jacket is lined with a fabric to clean the disk as it spins and to prevent the friction of plastic rubbing against plastic.
All disk drives have indicator lights that show when the disk is actually being used.
A diskette should never be removed while this light is on. You should always glance at this light before removing a diskette. Floppy disks, like audio and video cassettes, can be delete protected. On diskettes it is called write protection . It protects data from deletion and alteration.