SEO Glossary
Plain-English definitions for 66+ search engine optimisation terms. From technical fundamentals to AI search concepts.
Technical SEO
301 Redirect
A permanent HTTP redirect that passes link equity to the new URL and is the stan…
302 Redirect
A temporary HTTP redirect where Google typically keeps the original URL indexed …
Canonical Tag
An HTML link element that tells search engines which version of a page is the "m…
Core Web Vitals
Google's set of real-world performance metrics (LCP, CLS, INP) that measure user…
Crawl Budget
The number of pages Googlebot will crawl on your site within a given time period…
Crawling
The process by which search engine bots systematically browse the web to discove…
Cumulative Layout Shift (CLS)
A Core Web Vital that measures how much page content unexpectedly moves during l…
Duplicate Content
Substantially identical content appearing at multiple URLs, which can cause Goog…
Hreflang
An HTML attribute that tells search engines which language and region a page is …
HTTPS
The encrypted version of HTTP, required for Google's Page Experience signals and…
Indexing
The process by which search engines add crawled pages to their searchable databa…
Interaction to Next Paint (INP)
A Core Web Vital that measures the delay between a user interaction and the next…
JavaScript SEO
The practice of ensuring JavaScript-rendered content is crawlable and indexable …
JSON-LD
The recommended format for adding structured data to web pages, embedded as a sc…
Largest Contentful Paint (LCP)
A Core Web Vital that measures how long the largest visible element takes to loa…
Noindex
A directive that instructs search engines not to include a page in their index.
Orphan Page
A web page with no internal links pointing to it, making it difficult for search…
Page Speed
The speed at which a web page loads and becomes usable, a confirmed ranking fact…
Redirect
An instruction that sends users and crawlers from one URL to another, with diffe…
robots.txt
A plain-text file at the root of a domain that instructs crawlers which pages th…
Server-Side Rendering (SSR)
Generating full HTML on the server for each request so search engines receive co…
Structured Data
Standardised code (usually JSON-LD) added to web pages that explicitly describes…
Time to First Byte (TTFB)
The time between a browser requesting a page and receiving the first byte of a r…
XML Sitemap
A structured XML file listing your site's important URLs to help search engines …
On-Page SEO
Anchor Text
The visible, clickable text of a hyperlink that signals to search engines what t…
Heading Structure (H1–H6)
The hierarchy of HTML heading tags (H1–H6) used to organise page content, with H…
Image Alt Text
The alt attribute on <img> elements that describes an image to search engines an…
Internal Linking
Links from one page on a site to another page on the same site, used to distribu…
Meta Description
An HTML meta tag providing a 150–160 character summary of a page that may appear…
On-Page SEO
The practice of optimising individual web pages to rank higher and earn more rel…
Thin Content
Pages with little original value — low word count, duplicated content, or auto-g…
Title Tag
The HTML <title> element that appears as the clickable headline in search result…
URL Structure
The format and organisation of web page addresses, with keyword-rich, readable, …
Off-Page SEO
Backlink
A link from an external website pointing to your site, one of the most powerful …
Domain Authority (DA)
A Moz score (1–100) predicting how likely a domain is to rank in search results …
Link Equity (Link Juice)
The portion of a page's ranking power passed through its outbound links to the p…
Nofollow Link
A link with rel="nofollow" attribute that traditionally signals to search engine…
PageRank
Google's original algorithm for measuring the importance of web pages based on t…
Referring Domain
A unique domain that links to your site — the number of referring domains is oft…
Content
Content Quality
The degree to which a page's content satisfies user needs and meets Google's qua…
E-E-A-T
Experience, Expertise, Authoritativeness, and Trustworthiness — the framework Go…
FAQPage Schema
Structured data markup for FAQ content that helps search engines and AI tools ex…
Featured Snippet
A SERP feature displaying a highlighted answer box at the top of Google results,…
Keyword Cannibalization
When multiple pages on your own site compete for the same keyword, splitting ran…
People Also Ask (PAA)
A Google SERP feature showing related questions with expandable answer boxes pul…
Rich Results
Enhanced search result appearances (star ratings, images, prices, FAQs) enabled …
Search Intent
The underlying goal a user has when entering a search query — informational, nav…
Topical Authority
The depth and breadth of expertise a site demonstrates on a specific topic, buil…
AI & GEO
AI Overview
Google's AI-generated summary boxes that appear at the top of search results, sy…
Entity SEO
The practice of helping search engines understand and recognise the real-world e…
GEO (Generative Engine Optimization)
The practice of optimising content to be cited and featured in AI-generated sear…
Knowledge Graph
Google's database of entities and their relationships, used to power Knowledge P…
llms.txt
A proposed standard file at /llms.txt that helps AI language models understand a…
Analytics
Average Position
The mean ranking position of your pages in Google search results, as reported in…
Bounce Rate
The percentage of sessions where a user visited only one page and left without i…
CTR (Click-Through Rate)
The percentage of search impressions that result in a click to your website — (c…
Impressions
The number of times your page appeared in search results, regardless of whether …
Organic Traffic
Visitors who arrive at your site through unpaid search engine results, as distin…
Keywords
Keyword Clustering
Grouping semantically related keywords together so that a single page targets mu…
Keyword Difficulty
A metric (typically 0–100) estimating how hard it would be to rank in the top 10…
Keyword Research
The process of identifying search terms that your target audience uses and that …
Long-Tail Keyword
A specific, longer search phrase (usually 3+ words) with lower individual search…
SERP (Search Engine Results Page)
The page of results displayed by a search engine in response to a user's query, …
SERP Features
Enhanced elements in Google search results beyond standard organic listings — in…
Local SEO
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