Glossary
Short definitions of the website, search, and advertising terms used across the Learning Center, each linked to the guides that use it.
- Glossary
What is a 301 redirect?
A 301 redirect is a permanent server response that sends visitors and search engines from an old URL to a new one, and Google treats it as a signal that the new URL should be the one shown in search results.
- Glossary
What is a canonical tag?
A canonical tag is a link element, rel="canonical", that tells search engines which URL is the preferred version of a page when the same content is available at more than one address.
- Glossary
What is clickthrough rate (CTR)?
Clickthrough rate (CTR) is the share of people who click an ad or search result after seeing it, calculated as clicks divided by impressions.
- Glossary
What is a GCLID?
A GCLID (Google Click Identifier) is a parameter Google Ads adds to the landing page URL of each ad click when auto-tagging is on, used to track conversions and match offline sales back to the click.
- Glossary
What is Google Search Console?
Google Search Console is a free Google tool that shows how a website appears in Google Search, including the searches that show it, clicks, indexing problems, and links from other sites.
- Glossary
What is noindex?
Noindex is a rule, set in a robots meta tag or an HTTP header, that tells Google to drop a page from its search results even if other sites link to it.
- Glossary
What is robots.txt?
Robots.txt is a text file at the root of a website that tells crawlers which URLs they may visit, and Google says it manages crawling but doesn't keep a page out of search results.
- Glossary
What is an XML sitemap?
An XML sitemap is a file that lists a website's important pages so search engines can find and crawl them more efficiently, though Google says listing a page doesn't guarantee it will be indexed.