The 2SC3747 transistor is covered by this 95.9 KB PDF, categorised as a schematic but by its name a datasheet for a single component. The 2SC prefix in the Japanese JIS system identifies NPN types. Technicians open such a document in any PDF reader to check the lead arrangement, maximum collector voltage, power dissipation and package drawing. That information matters when a transistor tests shorted in circuit and must be replaced: an equivalent should match polarity and footprint and meet or exceed the ratings listed here.
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.