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.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
Reviews.io is a review collection tool for companies to collect merchant (company) & product reviews from genuine customers, then share these on Google.
Vercel is a cloud platform for static frontends and serverless functions.