Named only after the part 2SC4363, this 88 KB PDF is catalogued as a schematic but is most likely the manufacturer datasheet for that transistor. JIS designations beginning with 2SC denote NPN bipolar devices, and the marking on the case commonly drops the 2S, reading C4363. A technician relies on such a sheet for the lead order, package outline and limit values, then confirms the base-emitter and base-collector junctions in diode mode before choosing a substitute whose ratings meet or exceed the original.
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.