This is normally a read only drive where files are permanently stored.

uses laser technology to store the data hence comes with the data already on it for reading only (ROM = Read Only Memory) and hence cannot be written to for everyday storage.

There are now read/write CD-ROM drives that use special software to allow users to read from and write to these drives.

Much faster to access than a floppy but slower than a hard disk at present. Can hold up to a thousand megabytes of data.