Memcached is a memory caching platform, which is used to improve the overall performance of database-powered sites by caching the queries and the responses between the visitor and the server. To put it simply, every time a certain web page on such a website is opened, the script queries its database to fetch the info that should be shown to the visitor. If the latter clicks on a hyperlink to visit a different web page, the entire operation is carried out again and this leads to a lot of database calls and high server load, even more so if the site has a lot of concurrent visitors. Memcached "remembers" this information exchange, so in case any of these web pages is opened again, the script no longer has to call any info from the database, since everything is provided by the caching platform. In this way, the overall speed of your website will "soar" and you will have more happy visitors and they’ll be able to navigate through your website faster. Additionally, the Memcached platform updates its cache when any info in the database is changed, so the site users will never end up seeing old data.