Memcached is an object caching system, which is used to enhance the overall performance of database-powered websites by caching the requests and the replies between the website visitor and the server. Simply put, every time a given page on such a website is requested, the script connects to its database to fetch the info that should be shown to the website visitor. If the latter clicks on a link to open some other page, the entire procedure is performed again and this leads to lots of database requests and excessive server load, particularly if the site has a lot of concurrent visitors. Memcached "remembers" this information exchange, so in case any of these web pages is accessed again, the script no longer needs to cull any information from the database, as everything is provided by the caching platform. Thus, the overall load speed of your site will "soar" and you’ll have more pleased visitors and they’ll be able to surf through your site faster. Plus, Memcached updates its cache when any content in the database is updated, so the site users will never wind up seeing out-of-date data.