HD DVD and Blu-ray Disc
The following formats are not optical disc formats: HD DVD and Blu-ray Disc. These two formats are incompatible, and while they are sometimes confused with optical disc formats, they are not the same as compact discs (CDs) and digital versatile discs (DVDs). HD DVD and Blu-ray Disc are formats for storing digital video and audio content on discs that are used for high-definition media playback.
Another format that is not an optical disc format is CD-ROM. This industry-standard media format was designed to specify the volume and file structures of Compact Disk Read-Only Memory (CD-ROM) optical disks. It can be used to store and play back applications and data, but not for data storage like other optical disc formats.
In conclusion, HD DVD and Blu-ray Disc, and CD-ROM are the formats that are not optical disc formats. CDs and DVDs are the two formats that are considered to be optical disc formats. They are used for data storage, music playback, and film playback.