The phrase appears to be a technical description of a compressed archive, specifically a "solid archive" created using the RAR format . Technical Breakdown

: If any part of a solid archive becomes damaged, it may be impossible to extract any files that follow the damaged section in the data stream. Solid archives - WinRAR - Documentation & Help

According to experts from WinRAR and PeaZip , this "solid piece" approach offers specific trade-offs:

: Extracting a single file from the middle of a solid archive is slower because the software must process all preceding data in that "solid piece" to reach the target.

: This is the filename, where ".rar" is a proprietary archive format developed by Eugene Roshal.