What is the purpose of a Service Worker in a Progressive Web App?

Which Core Web Vital metric measures the time from when a page starts loading to when its main content is rendered?

What is the same-origin policy and how does CORS relate to it?

What is the critical rendering path and which technique best reduces its length?

What is XSS (Cross-Site Scripting) and what is the primary prevention strategy?

What problem does the Intersection Observer API solve compared to scroll event listeners?

In a micro-frontend architecture, what is the primary benefit of module federation (webpack 5)?

What is the purpose of requestAnimationFrame() compared to setTimeout for animations?