Generic PDF datasheet of 326 KB whose name says nothing about the component, manufacturer or part number, so you must open it to find out what it covers. A component datasheet typically lists pin assignments, electrical characteristics, timing data, package outlines and reference circuits. During repair it helps confirm correct supply and output voltages, identify a part from its top marking and choose a compatible replacement. It opens in any standard PDF reader.
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 @ic_mosfet_pdf_datasheets. 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.