Texas Instruments style literature document saved as a PDF of about 399 KB; the name is only a document code and does not state which device it describes. Files in the SDLS series are typically TI logic-family datasheets, so this one most likely covers a 74-series TTL part, but the specific chip must be checked by opening it. Once identified, it serves the usual purposes: pinout lookup, truth table, absolute maximum ratings and timing. Match the part number inside against the IC on the board 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_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.