Datasheet-style PDF, 142 KB, for the 74HC595D, the familiar 8-bit serial-in, parallel-out shift register with output latches; the D suffix usually marks the SO package. It is catalogued under schematics. The register appears in LED drivers, display boards and front panels where a few microcontroller lines expand into many outputs. With the pinout you can check data, clock, latch and output-enable pins with a scope and see whether outputs follow the serial stream. Verify the package before ordering a replacement.
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 @cyberlanelectonik. 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.