Archive labelled only abit M630, without board revision, chipset or content type in the name. Its size of about 660 KB is typical of a PDF schematic or service document for a desktop motherboard. Technicians use such material to follow power rails, check voltage regulator circuits and locate parts while chasing shorts or no-power faults. Unpack it to identify what is inside, and make sure the model and revision on the board silkscreen match before trusting component designators.
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 @schematicslaptop. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.