: Short for Blu-ray , indicating the high-definition disc source the video was ripped from.
: Likely an internal database ID or release number used by the group that uploaded the file.
In short, it is a high-definition Blu-ray rip of The Little Mermaid with subtitles included.
: The resolution (1280 x 720 pixels), which is standard high definition.
: The file extension , a common digital multimedia container format used for video and audio.
That file name is a standard string used in digital media to describe exactly what the video file contains.