SEO Dictionary: The 50 most important SEO terms explained
SEO is full of jargon and abbreviations that can make the field opaque. This dictionary collects the 50 most important SEO terms, explained without fluff.
A-B
Alt text: Descriptive text explaining an image to search engines and visually impaired users. Important for both SEO and accessibility.
Anchor text: The clickable text of a link. Descriptive anchors help Google understand context.
Authority: A general measure of a website's credibility in Google. Built through time, content and quality backlinks.
Backlink: A link from another website to yours. Still one of Google's strongest ranking factors — see how many you actually need to rank.
Black hat SEO: Aggressive methods that break Google's guidelines. Short-term gain, long-term risk of penalty.
Breadcrumbs: Navigation path at the top of a page. Helps users and Google understand site structure.
C
Canonical tag: An HTML tag telling Google which version of similar pages is the "main version". Critical to avoid duplicate indexing.
Core Web Vitals (CWV): Google's UX metrics: LCP, INP and CLS. Both ranking and conversion factors.
Crawl budget: How many pages Google will crawl on your site in a period. Small sites have effectively unlimited budget; large sites must manage it actively.
Crawler: The program Google uses to browse and index the web. Google's is called Googlebot.
CTR (Click-Through Rate): Share of impressions that result in a click. Key indicator of whether your title and description work.
D-G
Domain Rating (DR): Ahrefs' 0-100 metric for a domain's authority based on backlink profile.
Duplicate content: Content found on multiple URLs — confuses Google and dilutes authority.
E-E-A-T: Experience, Expertise, Authoritativeness, Trustworthiness. Google's quality principles.
Featured snippet: The direct answer at the top of search results.
GEO (Generative Engine Optimization): Optimising for AI-driven search engines like ChatGPT and Perplexity. Read more about AI SEO.
Google Search Console (GSC): Google's free tool for site owners. See the guide to finding backlinks in GSC.
H-K
H1, H2, H3: HTML heading levels. H1 is the main heading (one per page), H2/H3 are subdivisions.
Hreflang: Attribute telling Google which language and geography a page targets.
Indexing: The process where Google stores and categorises your pages. Without indexing, no display in search results.
Internal links: Links between pages on the same site. One of the most overlooked SEO wins — see the article on internal links.
Keyword: The word or phrase a user searches for. Foundation of all content strategy.
Keyword cannibalization: When multiple of your pages compete for the same keyword.
Keyword difficulty (KD): Estimate of how hard it is to rank for a keyword.
L-N
Link building: The process of actively building backlinks. See how I work with link building professionally.
Local SEO: Optimisation for local searches and Google Maps — read about local SEO.
Long-tail keywords: Longer, more specific keywords with lower volume but higher conversion.
Meta description: The text shown under the link in search results. Not a ranking factor, but affects CTR.
Meta title: The page's heading in search results. One of the most important on-page elements.
Nofollow / dofollow: Link attributes. Dofollow passes authority; nofollow doesn't.
Noindex: Meta tag asking Google not to index a page.
O-R
On-page SEO: Everything you do on the page itself — see how I work with on-page SEO.
Off-page SEO: Everything outside your page — primarily link building and digital PR.
PageRank: Google's original algorithm for measuring page authority based on incoming links.
Pagination: Splitting long lists across multiple pages. Can create SEO challenges if unhandled.
PBN (Private Blog Network): A network of sites built solely to provide backlinks. High-risk black-hat tactic.
Rankings: Your position in search results for a given keyword.
Redirect (301, 302): Forwarding from one URL to another. 301 = permanent (passes authority), 302 = temporary.
Robots.txt: File telling crawlers which parts of the site may be crawled.
S-Y
Schema.org / structured data: Code describing your content to search engines. Enables rich results.
SERP (Search Engine Results Page): The actual results page with organic results, ads, snippets etc.
Sitemap: XML file listing all important pages on your site.
Slug: The last, readable part of a URL.
Topic cluster: Content organised around a pillar topic with related sub-topics, all internally linked.
URL structure: How your URLs are built. Clean, descriptive URLs are easier for both users and Google to understand.
White hat SEO: SEO following Google's guidelines. Slower but sustainable.
YMYL (Your Money, Your Life): Topics affecting health, finance or safety. Google demands extra-high E-E-A-T here.
Need more?
This dictionary is a living document — updated over time. Want to go deeper? Read my other SEO guides or contact me for sparring through SEO strategy.
