ISO 9660 is a file system for optical disc media. The file system is an international standard available from the International Organization for Standardization (ISO). Since the specification is available for anybody to purchase, implementations have been written for many operating systems.
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 write-once and re-writable optical media. UDF was developed and maintained by the Optical Storage Technology Association (OSTA).
A disk image is a snapshot of a storage device's structure and data typically stored in one or more computer files on another storage device.
An optical disc image is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. ISO images contain the binary image of an optical media file system, including the data in its files in binary format, copied exactly as they were stored on the disc. The data inside the ISO image will be structured according to the file system that was used on the optical disc from which it was created.
Optical disc authoring, including CD, DVD, and Blu-ray Disc authoring, is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded ("burned") onto an optical disc.
Alcohol 120% is a disk image emulator and disc burning software for Microsoft Windows developed by Alcohol Soft. An edition named Alcohol 52% is also offered which lacks the burning engine. The software can create image files from a source CD/DVD/Blu-ray, as well as mount them in virtual drives, all in the proprietary Media Descriptor File format; images in this format consist of a pair of .mds and .mdf files.
A cue sheet, or cue file, is a metadata file which describes how the tracks of a CD or DVD are laid out. Cue sheets are stored as plain text files and commonly have a .cue filename extension. CDRWIN first introduced cue sheets, which are now supported by many optical disc authoring applications and media players.
IMG, in computing, refers to binary files with the .img filename extension that store raw disk images of floppy disks, hard drives, and optical discs or a bitmap image – .img.
A CloneCD Control File is a text descriptor with the extension .ccd used by CloneCD to store the subcode data of a CD/DVD image. These files need to be combined with an image file to be burned. It may also come with a subchannel file.
ImgBurn is an optical disc authoring program that allows the recording of many types of CD, DVD and Blu-ray images to recordable media. Starting with version 2.0.0.0, ImgBurn can also burn files and data directly to CD or DVD. It is written in C++. It supports padding DVD-Video files so the layer break occurs on a proper cell boundary.
MPEG-4 Part 14, or MP4, is a digital multimedia container format most commonly used to store video and audio, but it can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only filename extension for MPEG-4 Part 14 files as defined by the specification is .mp4. MPEG-4 Part 14 is a standard specified as a part of MPEG-4.
CDemu is a free and open-source virtual drive software, designed to emulate an optical drive and optical disc on the Linux operating system.
An NRG file is a proprietary optical disc image file format originally created by Nero AG for the Nero Burning ROM utility. It is used to store disc images. Other than Nero Burning ROM, however, a variety of software titles can use these image files. For example, Alcohol 120%, or Daemon Tools can mount NRG files onto virtual drives for reading.
A CD-ROM is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data computers can read, but not write or erase. Some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer.
Notable software applications that can access or manipulate disk image files are as follows, comparing their disk image handling features.
AcetoneISO is a free and open-source virtual drive software to mount and manage image files. Its goals are to be simple, intuitive and stable. Written in Qt, this software is meant for all those people looking for a "Daemon Tools for Linux". However, AcetoneISO does not emulate any copy protection while mounting.
WinCDEmu is an open-source utility for mounting disk image files in Microsoft Windows. It installs a Windows device driver which allows a user to access an image of a CD or DVD as if it were a physical drive. WinCDEmu supports ISO, CUE/BIN, CCD/IMG, NRG, MDS/MDF and RAW formats.
AppleDisk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Finder.
DAEMON Tools is a virtual drive and optical disc authoring program for Microsoft Windows and Mac OS.
