Gzip is a method of compressing files (making them smaller) for faster network transfers. It is also a file format. Compression allows the server to provide smaller file sizes which load faster for downloading. Enabling gzip compression is a standard practice, and used with most OnSpot downloads.

Files compressed with Gzip have a file extension [filename].gz or sometimes [filename].gzip.  A commonly used, free software app to open gzipped files on a PC, is 7-Zip and can be downloaded at https://www.7-zip.org/.   Most MACs have the ability to open gzipped files as they do any other compressed files i.e. [filename].zip by double clicking on the .gz file in your downloads folder or other folders on your desktop.