What is Time to First Byte (TTFB)?
Milliseconds until the server responds. High TTFB delays everything downstream including LCP, and usually points at hosting, edge caching, or server-render cost.
Related terms
Page Speed
How fast a page becomes usable, measured by field metrics like LCP and INP rather than single lab scores. Small gains compound commercially: a tenth of a second has moved retail conversions measurably.
Caching
Storing responses at the browser, CDN, or edge so repeat visits skip origin work. Correct cache headers and edge caching are usually the cheapest large performance win available.
CDN
A content delivery network serving static assets and cached pages from locations near the visitor. It cuts latency and TTFB globally without changing application code.
Technical SEO
The crawling, indexing, rendering, and performance work that lets search engines reach, understand, and serve your pages. It covers directives, architecture, speed, and structured data rather than words on the page.
Crawling
How search-engine bots discover pages by following links, sitemaps, and directives. If a URL is never crawled, it cannot be indexed no matter how good its content is.
Crawl Budget
The number of pages a search engine will crawl on a site in a given period, driven by server capacity and demand signals. Large or slow sites must spend it on indexable, valuable URLs.