Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.

jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.

jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.

Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.

Node.js is an open-source, cross-platform, JavaScript runtime environment that executes JavaScript code outside a web browser.

Varnish is a reverse caching proxy.

Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.