This identifies it as Season 1, Episode 1, potentially with a Part 2 or specific track designation. AAC / .mkv: The audio format and the file container type.
Likely a tag for the release group or the site it came from (SkymoviesHD). This identifies it as Season 1, Episode 1,
The video resolution (HD) and the compression format (high efficiency, smaller file size). This identifies it as Season 1