What does ISO come from? It comes from ISO 9660, which is a standard published by the International Organization for Standardization and it defines a file system for CD/DVD media. Its scope is to support different operation systems such as Microsoft Windows, Mac OS, etc.
DVDs may also use the ISO 9660 file system although the UDF (Universal Disk Format) file system is common among this type of media. 1999 is the latest update to the ISO 9660 standard.