Schematic for the Acer Aspire 7 A715-75G laptop, designed by Compal on board LA-J861P, supplied in a RAR archive. The LA-xxxxP code is Compal's board numbering, and the name confirms Compal as the ODM. Inside you should find a circuit diagram covering power rails, charging circuitry, CPU and GPU supplies and signal paths, usually as a PDF. Technicians use it to follow voltages, identify regulators and check component values; confirm the LA number on the motherboard first since revisions may differ.
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 @schematics_boardview. 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.