Stands for Amazon, indicating the source of the video was the Amazon Prime Video streaming service.
This is the most important part. It indicates that the previous version of this specific upload had a flaw—such as a stutter in the video, a missing subtitle track, or audio that didn't match the lip movements—and this new file is the corrected version. About the Film: I Believe in Unicorns (2014) ibelieveinunicorns20141080pamznwebripdd fix
This means the file was captured from a web stream rather than a direct "WEB-DL" (which is a lossless download of the stream). DD: Denotes Dolby Digital audio. Stands for Amazon, indicating the source of the