Glossary section
Mobile & speed
How your site performs on a phone, on cellular, in a real customer's hand. Most of your visitors are here — and Google ranks pages on this first.
14 definitions.
- Core Web Vitals — CWV
- Largest Contentful Paint — LCP
- Cumulative Layout Shift — CLS
- Interaction to Next Paint — INP, formerly FID
- Viewport meta tag
- Tap targets — button size on phones
- Body text size — minimum readable font size on phones
- Lighthouse — Google's audit engine
- PageSpeed Insights — PSI, pagespeed.web.dev
- First Contentful Paint — FCP
- Time to First Byte — TTFB, server response time
- CDN — Content Delivery Network, "the edge"
- Responsive design — mobile-first, adaptive layout
- Lazy loading — deferred loading, below-the-fold loading