Glossary

The words of SEO for people running several sites, explained simply, with the official source where there is one.

Canonical URL

The one URL search engines should treat as the main version of a page when several show the same content. You can suggest it, but Google makes the final choice.

Content decay

A page slowly losing search clicks over months, with nothing broken to explain it. Not to be confused with seasonality, a fault or a sudden update.

Core Web Vitals

Google’s three measures of how a page feels to real visitors: LCP for loading, INP for responsiveness, CLS for visual stability, judged at the 75th percentile.

Crawl budget

The set of URLs Google can and wants to crawl on a site. A real constraint on very large sites, and rarely the reason pages aren’t indexed on small ones.

Keyword cannibalisation

When several pages of one site compete for the same query, so none does as well as one strong page would. An SEO term, not Google’s, and often overdiagnosed.

Model Context Protocol

An open-source standard for connecting AI applications to outside systems. How an assistant such as Claude or ChatGPT can read figures held in another tool.