HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
The lite-youtube-embed technique renders the YouTube video inside the IFRAME tag only when the play button in clicked thus improving the core web vitals score of your website.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.