(UDF) A CD-ROMfile systemstandard that is required for DVD ROMs.UDF is the OSTA' s replacement for the ISO 9660 file system used on CD-ROMs, but will be mostly used on DVD.DVD multimedia disks use UDF to contain MPEGaudio and videostreams.To read DVDs you need a DVD drive, the kernel driver for the drive, MPEG video support, and a UDF driver.DVDs containing both UDF filesystems and ISO 9660 filesystems can be read without UDF support.UDF can also be used by CD-R and CD-RW recorders in packet writing mode.(1999-09-01)