Archive tied to the Quanta X12A board, 1.48 MB, packed as zip. Apart from the Quanta project code, the name gives no brand, revision or file type, so inspect the contents to see whether it holds a schematic, a boardview or both. Quanta is a large notebook ODM, and codes like X12A appear on its PCBs within DA0 part numbers. Material like this is used to trace supply rails, locate components and check signal paths during board-level repair. Match the code and revision on the actual board before trusting the references.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @notebookschematic. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.