CloudFlare is a powerful content delivery network. When you start using CloudFlare, your site becomes part of the CloudFlare network. This network routes your web site traffic through CloudFlare's global network of data centers.
CloudFlare stores duplicates of static content on its servers, thus, optimizing web content delivery. CloudFlare decreases page load times by serving your web site content from the CloudFlare server located nearest to your visitors. If a server in CloudFlare's network is very busy, web traffic is automatically routed to the next server nearest to your visitors.
CloudFlare also helps increase security and reduce wasted bandwidth by blocking threats and limiting abusive bots before they reach your server.