Technical SEO glossary

Understanding Technical SEO in a business context

Technical SEO is the work of making a website accessible to crawlers and usable in search. Start by separating discovery, crawling, indexing, and presentation. A page can pass one stage and fail the next, so an audit needs evidence from the stage where the problem occurred.

Using these definitions in your workflow

Read the response status before changing the copy. Then check crawl permissions, indexing instructions, and the preferred URL. For performance issues, inspect the affected page template and the real-user data when it exists. Treat a laboratory score as a diagnostic result rather than evidence that a customer could complete a task.

A plumbing service page that returns an error needs a different repair from a working page that Google regards as a duplicate. Record the affected URL, the symptom, and the setting that caused it. Verify the live response after the repair, then allow time for search engines to revisit the page.

Checking the evidence behind a report

Use the page response as the first piece of evidence, then examine the indexing instructions and the rendering path. A correctly configured canonical is different from a noindex rule, and a redirect is different from both. Check representative templates when a shared configuration changes. A homepage can work while a service template returns an error.

Verify the fix on a public request and retain the inspection record. Google may need to revisit the URL before its indexed observations reflect the live state you have corrected.

For practical context, use the matching website tool and compare the task with our service scope. Return to the full SEO glossary when the report uses terms from another topic.

Terms in this topic

Each entry below introduces a distinct concept. Open its explanation for the practical procedure and cautions. These definitions describe terminology, not a ranking guarantee. Check the original documentation when a report’s wording or a platform feature changes.

• Googlebot

  Googlebot is Google's web crawler for Google Search. It requests pages so Google can discover and process content; a request does not mean a page will be indexed.

• Noindex

  Noindex is a robots instruction that tells supported search engines not to include a page in search results. A crawler must be able to fetch the instruction to process it.

• Nofollow

  Nofollow is a link relationship value that signals a limited association with a linked page. Google treats nofollow as a hint; it is not an indexing block for the destination.

• X-Robots-Tag

  The X-Robots-Tag is an HTTP response header that carries indexing and presentation instructions for search engines. It works outside the page's HTML and can apply to non-HTML resources.

• Robots.txt

  Robots.txt is a file that tells supported crawlers which paths they may request. It controls crawling and is not a reliable way to keep a URL out of search results.

• XML sitemap

  An XML sitemap is a structured file listing URLs you want search engines to discover. Submitting a sitemap is a discovery signal, not a promise that its URLs will be indexed.

• Canonical tag

  A canonical tag is an HTML link element identifying the preferred URL among duplicate or very similar pages. It is a canonicalization signal, and Google can choose a different URL.

• Duplicate content

  Duplicate content is content available in substantially the same form at more than one URL. Search engines may choose one representative URL rather than show every version separately.

• Soft 404

  A soft 404 is a URL that appears missing or unhelpfully empty but returns a successful HTTP response. Google can treat that URL as an error rather than index its content.

• 404 error

  A 404 error is an HTTP response indicating that the requested resource could not be found. A useful error page can help visitors, but the server should still return the error status.

• 301 redirect

  A 301 redirect is a permanent HTTP redirect to another URL. It tells browsers and search engines that a resource has moved and points them to the new destination.

• 302 redirect

  A 302 redirect is a temporary HTTP redirect. It sends visitors to another URL while indicating that the original address is intended to remain relevant after the temporary change.

• Redirect chain

  A redirect chain is a sequence of redirects before a request reaches its final destination. Each extra hop adds another request and makes troubleshooting the route more difficult.

• Orphan pages

  Orphan pages are pages without discoverable internal links from the website's linked structure. A sitemap can list an orphan, but it does not replace a useful navigation path for visitors.

• Pagination

  Pagination is splitting a collection across separately addressable pages. Search engines need discoverable links between the pages to find content beyond the first portion of the collection.

• JavaScript SEO

  JavaScript SEO is making script-dependent content and links accessible to search engines. The rendered page, response status, and link structure matter alongside the original HTML response.

• Largest Contentful Paint (LCP)

  Largest Contentful Paint, or LCP, is a Core Web Vital that measures when the largest eligible content element becomes visible in the viewport during loading.

• Interaction to Next Paint (INP)

  Interaction to Next Paint, or INP, is a Core Web Vital describing page responsiveness to user interactions. It includes interaction processing and the wait before the browser displays the next frame.

• Cumulative Layout Shift (CLS)

  Cumulative Layout Shift, or CLS, is a Core Web Vital measuring unexpected visual movement. It captures layout instability rather than the time needed to load a page.

• Time to First Byte (TTFB)

  Time to First Byte, or TTFB, is the time from the start of a request until the first byte of the response arrives. It includes more than server processing alone.

• PageSpeed Insights

  PageSpeed Insights is Google's tool for examining page performance. It combines available real-user data with a Lighthouse laboratory test; those measurements describe different conditions.

• Structured data

  Structured data is machine-readable information describing the content and entities on a page. Search engines use supported markup to understand pages and assess eligibility for certain search features.

• Schema markup

  Schema markup is structured data that uses the Schema.org vocabulary. Correct vocabulary describes a page's content, while Google's separate documentation determines eligibility for Google rich results.

• JSON-LD

  JSON-LD is a format for representing linked data in JSON. On websites, it commonly appears in a script element to describe content without changing the visible page layout.

• Log file analysis

  Log file analysis is examining recorded server requests to understand crawling and response behavior. The usefulness of the conclusions depends on what the server recorded and whether bot identities were verified.

• IndexNow

  IndexNow is a protocol for notifying participating search engines when URLs change. A successful notification does not establish crawling or indexing, and Google is not a participating engine.

• Breadcrumbs

  Breadcrumbs are navigation links showing a page's place in a site's hierarchy. Breadcrumb structured data can describe that hierarchy to Google without replacing the visible navigation.

• Duplicate without user-selected canonical

  Duplicate without user-selected canonical is a Search Console indexing status for a duplicate URL with no declared preferred version. Google selected another URL to represent the content.

• Alternate page with proper canonical tag

  Alternate page with proper canonical tag is a Search Console indexing status for a duplicate that points to its preferred version. Exclusion of the alternate URL can be expected behavior.

• Index bloat

  Index bloat is an informal term for search indexes containing many low-value URLs from a site. The concern is unnecessary coverage and maintenance, not a Google metric with a fixed threshold.

• Image SEO

  Image SEO is making images accessible, discoverable, and suitable for their page context. Relevant text, crawlable image files, and appropriate delivery matter more than repeating keywords in filenames.

• Web crawler

  A web crawler is software that requests web resources to discover or update information. Different crawlers have different purposes, access rules, and ways of identifying themselves.

• Crawl budget

  Crawl budget is the amount of crawling a search engine is willing and able to do for a website. Google's guidance emphasizes large or rapidly changing sites, rather than ordinary small business websites.

• Page indexing report

  The Page indexing report is a Search Console report grouping discovered URLs by indexing status. An excluded URL can reflect either an intentional choice or a problem requiring investigation.

• Canonicalization

  Canonicalization is the process of choosing a representative URL from duplicate or very similar pages. Site owners suggest a preference, and search engines decide which URL to use.

• Page experience

  Page experience is Google's way of describing aspects of how people experience a web page. Useful content remains essential; a good experience score alone does not secure search visibility.

• Trailing slash

  A trailing slash is the slash at the end of a URL path. Search engines can treat slashed and unslashed paths as different URLs unless the site consistently consolidates them.

Sources

1. In-Depth Guide to How Google Search Works · accessed October 8, 2026
2. How to Specify a Canonical with rel="canonical" and Other Methods · accessed October 8, 2026
3. How HTTP Status Codes Affect Google's Crawlers · accessed October 8, 2026