RAR archive of 11.9 MB for the Samsung Galaxy J7 2016, model SM-J710FN. The name does not describe the contents, which in packages like this tend to be schematics, layout pages or service manual sections. Extract it with WinRAR or 7-Zip and open the documents in a PDF viewer. Such files help in tracing charging and power faults, locating components and test points, and planning board-level repairs. Check that the phone is an SM-J710FN, as J7 models from other years use different hardware.
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 @esquematicosdecelulares. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.