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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.