What is read only memory storage device-afloppy disk bhard disk c CDROM dnone?

CD-ROM is a read-only storage medium (CD-ROM is an acronym for Compact Disc Read-Only Memory). Floppy disks and hard-drives are both writeable mediums. Note that CD-R (Compact Disc Recordable) and CD-RW (Compact Disc Re-Writeable) are not the same as CD-ROM.