Small PDF datasheet titled only as lcd, so the exact display model or controller is not identified by the name. At 63 KB it is most likely a short reference for a character LCD module, giving pin functions, command set and timing, though the content should be opened to confirm. Such sheets help when wiring or troubleshooting a display on a microcontroller project or instrument, checking contrast voltage, enable strobe and data lines. Compare the module part number and pin layout with the document before use.
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 @datasheet. 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.