PDF schematic of MSI board MS-7507, revision 0A according to the file name, around 1.08 MB. MSI marks early engineering releases with codes like 0A, while later production revisions use numbers such as 1.0, so this may differ from retail boards. The drawings help with tracing power rails, checking VRM phases, following signals between chipset and connectors and identifying parts in a damaged area. Compare the revision printed on your PCB carefully, as early releases can have different components than shipped units.
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 @pepeelectronica. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.