PDF document of 41.7 KB for the 2SC4737, filed in the schematic category but named after a part rather than a board. The 2SC prefix is the Japanese JIS/JEITA designation for an NPN bipolar transistor, so the file is most likely a component datasheet. The name states nothing beyond the part number. Use it to confirm pinout, package outline and maximum voltage and current ratings before choosing a replacement, and compare the marking on the original device with the document, since SMD codes are often abbreviated.
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 @cyberlanelectonik. 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.