universal disk format (file format) (UDF)

The Universal Disk Format (UDF) is a universal file system defined by the Optical Storage Technology Association( OSTA) and standardized by ISO/ IEC under 13346, which was developed specifically for optical storage media.

The Universal Disk Format (UDF) is suitable for writing to various DVD and CD formats, including DVD-R and DVD-RAM as well as CD-R and CD-RAM. UDF allows writing and rewriting small blocks of data and erasing individual files. It can be used like a hard disk. The universal file format is available in three variants: UDF 1.02 for DVD-ROM, DVD-RAM and DVD-Video with a fixed size for the individual data blocks, UDF 1.5 for CD-R and CD-RW with different block lengths that can be adapted to the size of the files to be written, and UDF 2.0 as streaming media, where the data blocks can also be of different lengths.

The UDF format was developed specifically for DVDs and is the counterpart to ISO 9660 for compact discs (CD). It is cross- platform and supports all possible operating systems and languages and is characterized by the elimination of the limitations that ISO 9660 knows, such as the limited length of file names and the limited directory depth. In addition, UDF can distinguish between 8-bit and 16-bit characters and accommodate the different attributes of the operating systems.