Cloudflare Workers is a serverless execution environment that allows you to create entirely new applications or augment existing ones without configuring or maintaining infrastructure.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.