Indexed as a schematic, this 187 KB PDF is named after the 2SC2880, which the JIS 2SC prefix identifies as an NPN bipolar transistor. The document is probably a component datasheet, and the name gives no maker or edition. Repairers consult it to look up lead assignment, breakdown voltages, collector current, power dissipation and gain ranges before selecting a substitute. Testing the removed part with a multimeter in diode mode is easier with the pinout at hand. Match the package to the PCB footprint first.
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.