The name of the release group or individual who encoded and uploaded the file.

The file container (Matroska), which holds the video, audio, and subtitle tracks together. Summary

Season 1, Episode 1 (the series premiere titled "1923").

This is the video codec. AV1 is a modern, royalty-free format that provides better compression and visual quality than older codecs like H.264 or HEVC at the same file size.

This is the audio codec used. Opus is a highly efficient, high-quality format often used for transparent audio at lower bitrates.

The video was captured/recorded from a streaming service rather than a direct digital download (WEB-DL) or a physical disc.

Based on that filename, 1923: This is the title of the show, a Western drama starring Harrison Ford and Helen Mirren. It is a prequel to Yellowstone .