In the context of file sharing (like BitTorrent), a usually refers to a small segment of the total file. Large files are broken into hundreds or thousands of "pieces" (typically 256KB to 4MB each) so they can be downloaded from different users simultaneously.
The filename uses standard scene tagging to describe the quality and source: : The release year of the film. Cat.People.1982.PL.720p.BDRip.XviD.AC3-ODiSON.avi
: The name of the "release group" or individual who encoded and uploaded this specific version. .avi : The file container (Audio Video Interleave). ⚠️ Note on "Piece" In the context of file sharing (like BitTorrent),
If you are seeing this in a download manager, it means you have one fragment of the full movie. Cat.People.1982.PL.720p.BDRip.XviD.AC3-ODiSON.avi