Memcached is a data caching system, which is used to optimize the loading speed of database-powered Internet sites by caching the queries and the replies between the user and the server. Simply put, anytime a particular page on such a site is visited, the script sends a database query to get the information that should be displayed to the visitor. In case the latter clicks on a link to open some other web page, the whole process is executed again and this results in multiple database queries and higher server load, particularly if the site has lots of concurrent visitors. Memcached "remembers" this information exchange, so if any of these web pages is opened again, the script no longer has to call any info from the database, as everything is provided by the Memcached platform. In this way, the overall load speed of your website will "soar" and you will enjoy more gratified visitors and they will be able to surf through your site much faster. Additionally, the Memcached platform "refreshes" its cache whenever any information in the database is updated, so the site visitors will never end up seeing old data.