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| Web Caching (Image Source:- Vargonen ) |
Caching is a term used for naming the process of keeping the continually accessed files on a local area of computer so that the data retrieval becomes faster.
Web caching is done with the help of web browsers like Mozilla Firefox, Internet Explorer, Google Chrome, Netscape,Opera etc. The browser keeps the visited objects in their cache as per the directives contained in the HTTP header. This in return increases the performances and renders the results much faster.
The Process
1- Browser makes a request to the site.
2- The server responds with a 200 OK response code and returns the requested page.
3- The returned page may consist of the collection of objects such as images,css,Javascripts etc.
4- The returned objects comes with header containing the freshness information of the objects.
5- The browser stores the files and resources on its cache and when the user requests the same website again from the browser, it resends the requests to the server. The server returns 304 Not Modified response header, specifying the file in the cache of the browser is valid.
6- The browser presents the website to the user directly from its cache resulting in massive performance benefit.
Seo Benefit
The site speed is an important factor in the seo process. The site that loads fast is loved by the user. You can eliminate the unnecessary waste of bandwidth by using the correct cache control headers which would result in increased user performance and a decreased server load.
Example Cache Control Header
<filesMatch ".(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$"> Header set Cache-Control "public" Header set Expires "Mon, 22 Jun 2009 13:00:00 GMT" </filesMatch>
