Is a video format similar to MP4. The difference between the formats is their developers and protection. Apple company, has developed a format that has provided DRM-lock for M4V. Video files in this format are downloaded from iTunes.
A file with the CDDA file extension is a CD Digital Audio file that stores audio in the AIFF format. CDDA files are normally seen only when audio files have been ripped from an audio CD that uses the CD Digital Audio specification. This is most often done through the Apple iTunes program with the Audio CD burn option.