HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
PHP is a general-purpose scripting language used for web development.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
UptimeRobot is a web-based software that is designed to monitor the sites frequently to check whether any site is down owing to server problem or any bug in coding.