UDF or Universal Disk Format is a standard file system often used for DVDs. It is supported by many Operating Systems and is the default in Windows when storing files on optical disks like CDs and DVDs.
Universal Disk Format (UDF) is an open, vendor-neutral file system for computer data storage for a broad range of media. In practice, it has been most widely used for DVDs and newer optical disc formats, supplanting ISO 9660. Due to its design, it is very well suited to incremental updates on both recordable and (re)writable optical media. UDF was developed and maintained by the Optical Storage Technology Association (OSTA).
In engineering terms, Universal Disk Format is a profile of the specification known as ISO/IEC 13346 and ECMA-167.