Disc-burning glossary
Plain-English definitions of the CD, DVD and Blu-ray terms you'll meet when burning discs — 46 of them, with links to the full guides.
- BD-R
- A write-once Blu-ray Disc that can be recorded one time and cannot be erased, typically holding 25 GB on a single layer or 50 GB on a dual-layer disc. It is commonly used for high-capacity backups and high-definition video. Learn more →
- BD-R XL
- A high-capacity write-once Blu-ray format that uses three or four recording layers to store 100 GB or 128 GB on a single disc. It requires a BDXL-capable drive to read or write. Learn more →
- BD-RE
- A rewritable Blu-ray Disc that can be erased and recorded many times, typically holding 25 GB or 50 GB. It is suited to repeated backups where the same disc is reused. Learn more →
- BIN/CUE
- A two-file disc image format where the BIN file holds the raw disc data and the small CUE text file describes the track layout and how the data is organized. It is often used for audio CDs and mixed-mode discs. Learn more →
- Blu-ray Disc
- A high-capacity optical disc that uses a blue-violet laser to store far more data than a CD or DVD, typically 25 GB per layer. It is used for high-definition video and large backups. Learn more →
- Bootable disc
- A disc a computer can start up from directly, instead of booting from its hard drive, by including special boot information described by the El Torito standard. These are commonly used for operating-system installers and recovery tools. Learn more →
- Buffer underrun
- A burning error that occurs when data is not supplied to the drive fast enough to keep the write going, interrupting the continuous flow needed to record a disc. Most modern drives prevent it with buffer-underrun protection technology. Learn more →
- Burning
- The process of recording data, audio, or video onto a blank optical disc using a laser in the disc drive. The term comes from the laser physically altering the disc's recording layer to store information. Learn more →
- CD-DA
- Compact Disc Digital Audio, the standard format for music CDs defined by the Red Book specification. It stores uncompressed stereo audio that plays in virtually any CD player. Learn more →
- CD-R
- A write-once compact disc that can be recorded a single time and cannot be erased, typically holding about 700 MB of data or 80 minutes of audio. Once burned, its contents are permanent. Learn more →
- CD-RW
- A rewritable compact disc that can be erased and re-recorded many times, typically holding about 700 MB. It is useful for temporary storage or files that change often. Learn more →
- Cloning a disc
- Making an exact, sector-by-sector copy of a disc, usually by first creating a disc image and then writing it to a blank disc. The result is a duplicate that mirrors the original's structure. Learn more →
- Disc image
- A single file that contains the complete contents and structure of a disc, including its file system, so it can be burned to recreate an identical disc. Common formats include ISO, IMG, BIN/CUE, and NRG. Learn more →
- Disc-at-once (DAO)
- A burning method that writes the entire disc in one continuous operation without turning the laser off between tracks. It is preferred for audio CDs because it avoids gaps and produces a finalized disc. Learn more →
- Dual-layer DVD (DL)
- A DVD with two recordable layers on one side, roughly doubling capacity to about 8.5 GB compared with 4.7 GB on a single layer. It is used for larger videos and backups that exceed a standard DVD. Learn more →
- DVD-R
- A write-once DVD that can be recorded a single time and not erased, holding about 4.7 GB on a single layer. It is one of the most broadly compatible recordable DVD formats. Learn more →
- DVD-R DL
- A write-once dual-layer DVD using the "dash" standard, holding about 8.5 GB across two recording layers. It is suited to large files that do not fit on a single-layer disc. Learn more →
- DVD-RW
- A rewritable DVD using the "dash" standard that can be erased and re-recorded many times, holding about 4.7 GB. It is handy for backups and files you expect to update. Learn more →
- DVD+R
- A write-once DVD recorded a single time, holding about 4.7 GB, using the "plus" recording standard developed by the DVD+RW Alliance. It offers slightly different write management than DVD-R but is widely compatible. Learn more →
- DVD+R DL
- A write-once dual-layer DVD using the "plus" standard, holding about 8.5 GB across two recording layers. It is used when a single-layer 4.7 GB disc is too small. Learn more →
- DVD+RW
- A rewritable DVD using the "plus" standard that can be erased and re-recorded many times, holding about 4.7 GB. It supports convenient editing and overwriting of content. Learn more →
- El Torito
- The standard extension to ISO 9660 that lets an optical disc be made bootable, allowing a computer to start directly from the disc. It is what makes installer and recovery discs able to boot. Learn more →
- Finalizing
- The step that closes a disc so it can no longer be written to and can be read reliably in other drives and players. Finalizing writes the final table of contents and lead-out to complete the disc. Learn more →
- IMAPI2
- Image Mastering API version 2, the built-in Windows component that applications use to record data and audio to optical discs. cdBurner's local agent uses IMAPI2 to perform burns on Windows. Learn more →
- IMG file
- A disc image file that stores a raw copy of a disc's contents and can be burned to recreate it. Some IMG files are interchangeable with ISO images, while others use a raw sector format. Learn more →
- ISO 9660
- The original cross-platform file system standard for CD-ROMs, ensuring discs can be read on many different operating systems. Its strict naming limits led to extensions such as Joliet and UDF. Learn more →
- ISO image
- A disc image file, usually ending in .iso, that contains the full contents and file system of an optical disc in a single file. Burning an ISO recreates an exact copy of the original disc. Learn more →
- Joliet
- A Microsoft extension to ISO 9660 that supports longer file names and Unicode characters than the original standard allowed. It improves how discs created on Windows display file names. Learn more →
- Lead-in
- An area at the start of a recorded disc session that holds the table of contents and timing information the drive reads before the actual data. It is written when a session is closed. Learn more →
- Lead-out
- An area written at the end of a disc session that marks where the recorded data stops. Writing the lead-out is part of closing a session or finalizing a disc. Learn more →
- M-DISC
- A write-once archival disc that records data into a rock-like, inorganic layer designed to resist degradation far longer than standard recordable discs. It is intended for long-term data preservation and requires an M-DISC-capable burner. Learn more →
- Mount Rainier
- A standard that lets rewritable discs be used much like a USB drive, with built-in defect management and drag-and-drop writing without separate formatting steps. It requires both drive and operating-system support.
- Multisession disc
- A disc that allows data to be added in more than one separate burning session over time, rather than all at once. Each session adds its own table of contents until the disc is finalized. Learn more →
- NRG file
- A disc image format created by the Nero burning software that stores the contents of a disc in a single file. It can be burned to disc or converted to a more universal format such as ISO. Learn more →
- Optical disc
- A flat, round storage medium such as a CD, DVD, or Blu-ray that is read and written using a laser. Data is stored as microscopic marks along a spiral track on the disc surface. Learn more →
- Power calibration
- A quick test a drive runs before burning to set the correct laser power for the specific disc. A power calibration error means the drive could not find a suitable setting, often due to a poor-quality or incompatible disc. Learn more →
- Red Book
- The standard that defines the audio CD (CD-DA) format, specifying how music is stored so it plays in standard CD players. Discs burned to this standard are normal audio CDs rather than data discs. Learn more →
- Rewritable disc
- A disc such as CD-RW, DVD-RW, DVD+RW, or BD-RE that can be erased and recorded many times. It contrasts with write-once discs, which can be recorded only a single time. Learn more →
- Ripping
- Copying the contents of a disc, such as the tracks of an audio CD, into files on a computer. cdBurner can rip an audio CD into digital audio files for storage or playback. Learn more →
- Session
- A single recorded segment on a disc, consisting of a lead-in, the recorded tracks, and a lead-out. A disc can contain one session or, on a multisession disc, several added over time. Learn more →
- Table of contents (TOC)
- An index recorded on a disc that tells the drive what tracks or sessions are present and where they begin. It is written into the lead-in when a session is closed. Learn more →
- Track-at-once (TAO)
- A burning method that records each track as a separate operation, turning the laser off between tracks. It is flexible for adding tracks but can leave small gaps, making disc-at-once preferable for seamless audio CDs. Learn more →
- UDF
- Universal Disc Format, a modern file system used on DVDs, Blu-ray discs, and large data CDs that supports big files and drag-and-drop writing. It overcomes the size and naming limits of the older ISO 9660 standard. Learn more →
- Verifying a burn
- Comparing the data written to a disc against the source after burning to confirm it was recorded correctly. A successful verification gives confidence the disc is readable and complete. Learn more →
- Write speed
- How fast a disc is recorded, expressed as a multiple such as 8x or 16x of the format's base speed. Lower speeds can improve reliability and compatibility, especially on audio CDs and lower-quality discs. Learn more →
- Write-once disc
- A disc such as CD-R, DVD-R, DVD+R, or BD-R that can be recorded only a single time and cannot be erased. It contrasts with rewritable discs, which can be reused. Learn more →
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