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.

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

Apache is a free and open-source cross-platform web server software.

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.

Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.

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

OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.

Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.

Bluehost is a large web host known for its WordPress expertise, variety of “one-stop-shop” services, and bargain prices.