Schematic PDF of 265 KB with an uninformative numeric name, 0001534, offering no brand, model or board number. Its small size suggests a component datasheet or reference circuit rather than a full board drawing, so review the first page to see what it covers. Documents like this are used to look up pin functions, expected voltages and recommended external parts, which helps in testing or replacing a chip and confirming the values of nearby resistors and capacitors.
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 @one5technology. 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.