Schematic package for the Huawei Y9 2019 smartphone, supplied as a 1.50 MB zip archive. The name gives no board number or revision, so confirm the mainboard marking against the diagrams before relying on them. Inside you can usually expect PDF circuit pages or images covering the PMIC, charging path, display and camera connectors and RF sections. Technicians use phone schematics like this to trace power rails, find test points for voltage measurements and work out which components sit on a shorted line.
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 @phoneSchematics. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.