HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
Vercel is a cloud platform for static frontends and serverless functions.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.