When a user visits your website a call is made to your server to deliver the requested content. Gzip compresses your webpages and style sheets before sending them over to the browser. This drastically reduces transfer time since the files are much smaller.
Gzip compression is really effective because CSS files and HTML files use a lot of repeated text and have plenty of whitespace. Since Gzip compresses common strings, this can reduce the size of pages and style sheets by up to 90%.
Posted in: Cache