Welcome to the most comprehensive SEO glossary you’ll ever need. Updated for 2026 and beyond, this guide covers traditional SEO terms, evolving practices like Answer Engine Optimisation (AEO), Geo-targeting, semantic SEO, and AI-driven trends like LLMO and llms.txt.
Whether you are a business owner, marketer, an SEO agency or web developer, bookmark this page as your go-to resource.
A
Accessibility – Designing and developing websites that can be used by everyone, including people with disabilities. In SEO, accessibility improves usability and helps search engines better understand and rank content. It involves proper heading structure, alt text for images, keyboard navigation, and readable contrast.
AdWords (now Google Ads) – Google’s advertising platform where businesses bid on keywords to display ads in Google search results and its advertising network.
Algorithm – A complex set of rules or formulas used by search engines to rank websites and deliver the most relevant results for user queries.
ALT Text – Alternative text for images that describes what the image shows. Crucial for accessibility and helps search engines understand image content.
Anchor Text – The clickable text in a hyperlink. Relevant anchor text improves SEO and helps define the context of the linked page.
Analytics – Data tracking tools like Google Analytics used to monitor traffic, user behaviour, conversions, and more.
Answer Engine Optimisation (AEO) –Optimising your content to be directly cited by answer engines like ChatGPT, Google’s SGE, Alexa, or Siri. AEO involves clear Q&A formatting, structured data, and conversational language to help AI extract accurate answers.
A/B Testing – Comparing two versions of a webpage or element to determine which performs better in terms of conversions, bounce rate, or other metrics.
Authority – A measurement of the credibility of a domain or page based on backlinks, content quality, trust signals, and user experience.
Audit (SEO Audit) – A detailed analysis of a website’s technical, on-page, and off-page SEO health.
Auto-generated Content – Content produced by software (often AI). If not reviewed and edited, it may be flagged by search engines as low quality.
B
Backlinks – Inbound links from one website to another. A critical factor in ranking.
Black Hat SEO – Unethical SEO techniques that violate search engine guidelines.
Bounce Rate – Percentage of users who leave your site without interacting.
Bot (Crawler/Spider) – A program used by search engines to index the web.
Branded Search – Searches that include a business or product name.
Breadcrumbs – A navigation aid showing users the path to the current page.
Broken Links – Links that lead to a non-existent page. They hurt UX and SEO.
C
Canonical Tag – Prevents duplicate content issues by specifying a preferred URL.
Click-Through Rate (CTR) – Percentage of users who click on a link vs. those who view it.
CMS (Content Management System) – Platform used to create and manage content (e.g., WordPress, Shopify).
Content Marketing – Using content to attract and engage audiences organically.
Conversion – Turning a visitor into a customer or lead.
Core Web Vitals – Google’s user experience metrics: LCP, FID, and CLS.
Cumulative Layout Shift (CLS) – Measures visual stability. Pages should maintain a CLS score of less than 0.1 to ensure elements don’t shift unexpectedly.
Crawling – The process by which bots scan websites to index them.
D
De-indexing – Removal of a URL or site from search results.
Disavow Tool – A Google tool used to tell bots to ignore bad backlinks.
Dwell Time – How long a user stays on a page before returning to search results.
Duplicate Content – Identical or very similar content on different pages. Can hurt SEO.
E
E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness) – Guidelines Google uses to assess content quality.
Engagement – Metrics like time on site, bounce rate, and pages per session.
Evergreen Content – Content that remains relevant over time.
External Links – Outbound links from your site to another. Can add authority if well used.
F
Featured Snippet – A highlighted summary at the top of Google search results.
Footer Links – Links placed in the bottom of a website, used for navigation or SEO.
Frequency (of posting) – How often you publish content can affect SEO and visibility.
First Input Delay (FID) – Measures interactivity. FID should be less than 100 milliseconds. (Note: FID is being replaced by Interaction to Next Paint – INP)
G
Geo Services – Local SEO strategies and tools that target users in specific regions.
Google Business Profile – A free business listing for managing local search visibility.
Google Search Console – A tool to monitor, maintain, and troubleshoot site presence in Google.
Google Penalty – A reduction in rankings due to guideline violations.
Gray Hat SEO – SEO techniques that fall between ethical (white hat) and unethical (black hat).
H
Header Tags (H1–H6) – HTML tags that structure content and indicate topic hierarchy.
Heatmaps – Visual tools showing where users interact most on a webpage.
Hidden Text – Text not visible to users but indexed by bots. Risky if misused.
Hreflang – A tag that helps search engines serve the correct language or regional URL.
I
Indexing – The process of storing and organizing content in a search engine database.
Internal Links – Hyperlinks pointing to other pages within the same website.
Impressions – Number of times a page or link is shown in search results.
Inbound Links – Another term for backlinks.
IP Targeting – Delivering content based on a user’s IP address for geolocation.
J
JavaScript SEO – Optimising JavaScript-heavy websites so they’re crawlable and indexable.
JSON-LD – A format for implementing structured data to improve SEO and AEO.
K
Keyword Research – Finding search terms your target audience uses.
Keyword Stuffing – Overuse of keywords to manipulate rankings. Penalised by Google.
Knowledge Panel – A box that shows entity information on the right side of Google search.
L
Landing Page – A standalone web page designed for a specific marketing campaign.
Latent Semantic Indexing (LSI) – A method to identify relationships between terms in content. (Now replaced by more advanced NLP models.)
Lead Magnet – Valuable content offered to users in exchange for their info. Drives traffic and conversions.
Link Building – The practice of acquiring backlinks from other websites.
Link Juice – The SEO value passed from one page/site to another via links.
LLMO (Large Language Model Optimisation) – The process of optimising web content to be cited or surfaced by generative AI like ChatGPT, Gemini, or Claude.
llms.txt – A proposed file (like robots.txt) to control how large language models access and use a site’s content. An emerging standard in AI-era SEO.
Largest Contentful Paint (LCP) – Measures loading performance. LCP should occur within 2.5 seconds of when the page first starts loading.
M
Meta Description – A short page summary shown in search results.
Meta Tags – Tags in HTML that provide metadata about the page.
Mobile-First Indexing – Google indexes the mobile version of your site first.
Markup (Schema) – Structured data added to HTML to improve how content is read by search engines.
N
NAP (Name, Address, Phone) – Critical for local SEO consistency.
Negative SEO – Attempts to damage a competitor’s SEO using black hat techniques.
NoIndex – A meta tag that tells search engines not to index a page.
Nofollow – An HTML attribute that tells bots not to pass link equity.
O
Organic Search – Search traffic that comes from non-paid listings.
On-Page SEO – Optimisations made on the actual page content (headers, images, keywords).
Off-Page SEO – Actions taken outside the site (like link building) to improve rankings.
Open Graph Tags – Tags that control how content is previewed on social platforms.
P
Page Speed – The load time of a webpage. Influences rankings and UX.
Pogo-sticking – When users click a result, bounce back, and try another. A negative engagement signal.
PPC (Pay Per Click) – A paid search model where advertisers pay when users click.
Position Zero – The top spot in search results, often a featured snippet.
Page Authority – A score (0–100) predicting how well a page will rank.
Q
Query – A word or phrase a user types into a search engine.
Quality Score – A Google Ads metric for ad quality and relevance.
QDF (Query Deserves Freshness) – Google’s mechanism to prioritise fresh content for trending topics.
R
Redirects – Forwarding one URL to another. 301 (permanent), 302 (temporary).
Rich Snippets – Enhanced search results showing reviews, pricing, availability, etc.
Robots.txt – A file that tells search engines which parts of a site to crawl or ignore.
Ranking Factor – Any element search engines use to decide search rankings.
S
Schema Markup – Code that helps search engines return more informative results.
Search Intent – The purpose behind a search query (informational, transactional, navigational).
Search Engine Results Page (SERP) – The page showing results from a search.
Sitemap – A file listing all important URLs on your site.
Slug – The part of a URL that identifies a specific page.
Social Signals – Likes, shares, and comments. Indirect SEO signals.
SSL Certificate – Secure Sockets Layer. Websites with HTTPS have higher trust and ranking.
T
Title Tag – HTML element that defines the title of a webpage.
Traffic – Number of visitors to a website.
Thin Content – Low-quality content with little to no value. Penalised by Google.
Technical SEO – Backend optimisation including site speed, indexing, and structure.
Topical Authority – Demonstrating in-depth knowledge on a specific topic cluster.
U
UI (User Interface) – The look and feel of a website’s interface.
URL (Uniform Resource Locator) – A page’s web address.
User Experience (UX) – How a person interacts and feels when using a website.
UTM Parameters – Tags added to URLs to track campaign performance.
V
Voice Search SEO – Optimising content for queries spoken into smart devices.
Video SEO – Optimising videos for indexing and ranking.
Vertical Search – Search within specific categories like images, news, or shopping.
W
Web Core Vitals – Google’s performance metrics: loading, interactivity, and visual stability.
White Hat SEO – Ethical SEO practices aligned with search engine guidelines.
Web Crawlers – Programs that scan the web and index pages.
Word Count – Amount of content on a page. Ideal length depends on topic and user intent.
X
XML Sitemap – A structured file that lists all the URLs on a site for bots to index.
Y
YMYL (Your Money or Your Life) – Topics that impact health, finance, or safety. Require high E-A-T.
Z
Zero-Click Searches – Queries answered directly in search results, no click required.