Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Envoy is an open-source edge and service proxy, designed for cloud-native applications.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Lightbox is small javascript library used to overlay images on top of the current page.
Open Graph is a protocol that is used to integrate any web page into the social graph.