cdnjs is a free distributed JS library delivery service.
Chart.js is an open-source JavaScript library that allows you to draw different types of charts by using the HTML5 canvas element.
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.