Datasheet PDF for the 2SC4983, 144 KB, recorded in the schematic section of the index. The name holds only the part number. A 2SC number under JIS/JEITA rules belongs to an NPN bipolar transistor, so the document describes a single component, probably with characteristic curves given its size. Use it to confirm terminal order before diode-mode measurements, to check maximum ratings against the circuit conditions, and to verify footprint compatibility before fitting an alternative part.
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.