Memcached is a caching system, which is used to supercharge the load speed of database-powered websites by caching the calls and the replies between the website visitor and the server. In other words, anytime a given web page on such a site is accessed, the script calls its database to request the information that should be displayed to the visitor. If the latter clicks on a link to visit some other web page, the whole operation is carried out again and this results in a lot of database queries and high load on the server, especially if the site has a lot of concurrent visitors. Memcached "memorizes" this exchange of information, so if any of these pages is requested again, the script no longer has to pull any info from the database, since everything is delivered by the caching platform. Thus, the overall speed of your website will "soar" and you will get more gratified visitors and they’ll be able to navigate through your website faster. Moreover, Memcached "refreshes" its cache whenever any info in the database is edited, so the site visitors will never wind up seeing outdated data.