Huawei Y320 package of 2.53 MB whose name gives nothing beyond the model number, so its exact contents are unknown until extracted. It may contain a schematic, service guide or firmware for this entry-level phone. Technicians use such files to identify components, follow charging and supply circuits and find points to measure on the PCB, or to restore software. Verify that the board revision and model variant on the handset match the documents before relying on component designators or flashing anything.
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_Mobile. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.