PDF schematic for the Samsung SM-A720F, about 3.58 MB, with no board revision indicated in the name. Board-level technicians rely on documents like this to follow voltage rails out of the PMIC, check the battery and charging path, trace display and camera interface lines and spot the components sitting on a shorted net. Any PDF application can open it. Check the PCB markings of the phone being repaired against the schematic, since regional variants can differ in fitted parts.
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 @schematic_mobiles. 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.