Gzip may refer to any of the following:
1. Short for GNU zip, Gzip is a compression tool on Unix-like systems which use the GNU command line tools. It was developed by Jean-Loup Gaily and Mark Alder, and released on October 31, 1992. Files compressed with gzip usually contain the file name extension .gz.
2. When referring to HTTP and content-encoding, HTTP/1.1 introduced gzip as a way for a web server to compress content before sending it to the visitor. Using gzip, a page loads faster because of the smaller size and can also reduce overall bandwidth costs.
For example, this web page is 7.65 KB in size and the gzipped version of this page is 2.47 KB, which is a data savings of 67.71%. If you took this example, multiplied it by hundreds-of-thousands of pages, you can see how this one change can help. This example is also just the .htm file, which does not include any external .CSS files that can also be gzipped.