Zip archive of 1.40 MB for the MSI MS-6725 board, with the name giving no hint of the contents, so it may hold a schematic, a BIOS image or both. MS- followed by four digits is the internal project number MSI prints on its own PCBs, normally near the expansion slots, so compare it with the board before use. Unpack the archive and check each file: a PDF schematic helps trace power rails and signals, while a ROM image goes onto the BIOS chip with a programmer after backing up the original.
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 @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.