Datasheet for a 2x16 character LCD module, meaning two lines of sixteen characters, supplied as an 87.6 KB PDF. Modules of this format are commonly driven by an HD44780-compatible controller, and documents of this kind usually cover the 14 or 16 pin interface, instruction set, initialisation sequence and backlight connections. It helps when a display shows blank boxes or garbage, guiding checks of the contrast pin, enable line and 4-bit or 8-bit wiring. Confirm the module pinout, as some panels place the connector differently.
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.