Craft CMS is a content management system for building bespoke websites.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
SEOmatic facilitates modern SEO best practices & implementation for Craft CMS 3.