When a user types your website url in browser and hits enter, browser sends request to server. Server responds to that request in the form of reply by giving back the requested document. That document can be of any size, typically if we take javascript files, it can be between 100 to 200 KB. Is there is any way to reduce this size so that the downloading can be faster ? Answer is "yes", that's what gzip compression does. It compresses the document size to almost 70% of the original. The major benefit of gzip compression is that it reduces bandwith by reducing the size of the response from the server.