A file with the extension is a compressed archive created using the 7-Zip software or a compatible archiver. Because "NNAGU" is not a standard system filename, it likely represents a specific dataset, project backup, or user-created collection of files. Understanding the .7z Format
Popular paid alternatives that also support the format.
Archives can be encrypted using the robust AES-256 standard , which is also used by governments and financial institutions.
It typically compresses data 30–70% better than the standard ZIP format.