: The file extension for Matroska Video . It is a flexible container format that can hold multiple video, audio, and subtitle tracks in one file. The Ecosystem of These Files
is technically Standard Definition, it is often labeled as "HD" in these contexts to indicate it was sourced from a high-definition master (like a Blu-ray or high-quality stream) but compressed for a smaller file size.
: Typically refers to the date the file was uploaded or the date of the content's release.