Glossary: analytics and example domain terms

Glossary

Short explanations of the terms used on this site, with links to the guides.

Example domain: A domain name used in documentation to stand for “your site”. Reserved example domains such as example.com lead nowhere; registered look-alikes such as example-petstore.com reach a real server. See example domains.
Classic Analytics (ga.js): Google Analytics tracking code from 2007, using _gaq.push() and pageTracker. It no longer collects data. See the Analytics guide.
Universal Analytics (analytics.js): The successor of Classic Analytics, using ga('create', …). It stopped processing data on 1 July 2023 and was switched off on 1 July 2024.
Google Analytics 4: The current version of Google Analytics, installed with the Google tag or Google Tag Manager. Cross-domain settings are made in the admin.
Google tag (gtag.js): The script that sends data to Google Analytics 4 and other Google products. It is configured with gtag('config', …) and gtag('set', …).
Cross-domain measurement: Counting one visit across several of your own domains, such as a shop and a checkout provider, as a single session.
_setDomainName: A Classic Analytics setting for the cookie domain. Google’s examples used 'example-petstore.com', '.example-petstore.com' or 'none'. Google Analytics 4 sets the cookie domain automatically.
_link and _linkByPost: Classic Analytics functions that passed visitor cookies to another domain through a link or form. In the examples they pointed at dogs.example-petstore.com and example-commerce-host.com/petStoreCart.
Linker and _gl: The Google tag feature that adds a _gl parameter to links between your configured domains, so the visit continues on the other domain. Older code used __utma and similar parameters.
Unwanted referrals: A Google Analytics 4 list of referring domains that should not start a new session, such as a payment provider.
Self-referral: Your own site showing up as the source of its traffic, usually because cross-domain measurement is missing or misconfigured.
Structured data (JSON-LD): Machine-readable information about a page in a <script type="application/ld+json"> block, using the schema.org vocabulary.
WebSite markup: A structured data block with your site’s name and url, placed on the home page. Google uses it when choosing the site name shown in results.
SearchAction and the sitelinks search box: Markup that asked Google to show a search box below a site’s result, sending searchers to the target address. Google stopped showing the box on 21 November 2024. See the search box guide.
Change of Address tool: A Search Console tool that tells Google a site has moved to a new domain. It requires both domains as verified properties and 301 redirects. See the site move guide.
301 redirect: A permanent redirect from an old address to a new one.
Canonical URL: The preferred address of a page, given with <link rel="canonical">. On this site, every address points to the home page as canonical.
hreflang: Annotations that link the language versions of a page, so search engines show the right one.
Base URL: The address an API client puts in front of every request path, such as https://api.example.com/v2. It belongs in configuration. See the API guide.
410 Gone: The HTTP status this domain returns to API requests: the resource is not available here and will not be.
application/problem+json: The standard format for HTTP API error details (RFC 9457), with type, title, status and detail.
Credential rotation: Revoking a key, token or password and issuing a new one. Required when a credential was sent to the wrong server. See leaked credentials.