At 237 KB, this PDF is labelled 2SC3382 and nothing more, so it describes a part rather than a specific device. By JIS numbering, 2SC identifies an NPN bipolar transistor for high-frequency use, which makes a manufacturer datasheet the likely content. Technicians consult such sheets for the lead configuration, safe operating limits and characteristic curves when testing a suspect stage or picking an equivalent. Open it in a standard PDF viewer and confirm the part marking before substituting anything.
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.