PDF datasheet, 446 KB, named SDLS169 with no part number or device description given. That code fits the Texas Instruments literature system for standard logic datasheets, so the exact IC should be confirmed from the opening page. Expect pin assignments, logic diagrams, function tables and DC and switching parameters. When repairing digital circuitry, these let you verify that the chip receives correct power, that outputs respond properly to inputs, and that a chosen substitute matches the original package.
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_technar_org. 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.