Boardview archive for the ASRock B550M Pro SE desktop motherboard, revision 1.01, 655 KB. ASRock marks the model and revision on the PCB, and both should match before you trust part positions. The layout lets a technician locate VRM components for the AM4 socket, the SPI BIOS chip, memory power parts and test points, follow nets between them and track down shorts or missing components. It opens in standard boardview programs such as OpenBoardView or FlexBV after extraction.
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 @BoardSchematic. 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.