HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
LazySizes unveilhooks plugin extends lazySizes to lazyload scripts/widgets, background images, styles and video/audio elements.
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.