Short for CD File System, CDfs, in Linux systems, is a file system first introduced August 21, 1999 that exports all tracks and boot images on a CD as normal files. In Windows, CDFS is the Windows driver for CD-ROM players. The CDFS replaces MSCDEX that was used for MS-DOS and is a 32-bit program that runs in protected mode. Also, CDFS uses a VCACHE driver to control the CD-ROM disk cache allowing for a smoother play back.
To mount a CD using the CDfs you'd type a command similar to the example below.
mount -t cdfs -o ro /dev/cdrom /mnt/cdfs
Once the drive is mounted, its contents could be listed using a command similar to the example below.
ls -l /mnt/cdfs