A PDF document for the 2SC4884, filed under schematics but by its name a component datasheet rather than a board diagram. Under the Japanese JIS numbering system, the 2SC prefix marks an NPN bipolar transistor. The name gives no manufacturer, package or ratings, so read those from the sheet itself. Technicians use such a document to confirm pinout, maximum voltage and current, and gain before fitting a replacement. At 106 KB it opens in any PDF reader. Compare the marking on the part with the number before relying on it.
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.