SEO (Search Engine Optimization) has its own jargon, and it puts people off fast when they're starting out. This guide explains 39 essential terms so you can follow what search engines are doing with your site. I've added the ones that matter in 2026, now that an AI answer sits above everything else on the page.
Technical Fundamentals
1. Crawlability
A site's ability to be explored by search engine bots (Googlebot, Bingbot, etc.). A "crawlable" site allows bots to discover and analyze its pages. I went through how to improve it in my guide on website crawlability.
2. Indexability
The possibility for a page to be added to the search engine's index. An indexed page can appear in search results.
3. SERP (Search Engine Results Page)
The results page displayed after a search. Includes organic results, paid ads, and rich features.
4. Core Web Vitals
Metrics measuring user experience:
- LCP: loading speed
- INP: interaction responsiveness
- CLS: visual stability
These metrics feed your ranking and your conversion rate. My store speed guide covers how to move them.
5. Robots.txt
A text file giving instructions to bots about which pages to explore or ignore.
6. Canonicalization
Indicating the primary version of a page when multiple URLs lead to the same content.
7. Sitemap
An XML file listing all important pages on your site to facilitate their discovery.
8. Redirect
Automatic forwarding from one URL to another. Common types:
- 301: permanent redirect
- 302: temporary redirect
301s become non-negotiable the day you change a URL or a platform, because everything you built on the old address goes in the bin otherwise. I cover it in my Shopify migration guide.
On-Page Elements
9. Title Tag
HTML element defining the page title, displayed in search results.
<title>Your Optimized Title - Site Name</title>10. Meta Description
Short description appearing below the title in SERPs. Influences click-through rate but not direct ranking.
11. Keywords
Terms and phrases searched by users. The basis of any SEO strategy.
12. Internal Links
Links pointing to other pages on your own site. Essential for navigation and "SEO juice" distribution.
13. Alt Text
Text description of images, important for accessibility and image SEO.
Off-Page Elements
14. Backlinks
Links from other sites pointing to yours. A major ranking factor, and one of the hardest things to earn honestly.
15. Rich Snippets
Enhanced search results with additional information: stars, price, availability, etc.
Metrics and Analytics
16. Bounce Rate
Percentage of visitors leaving the site after viewing only one page.
17. Loading Time
Time needed to fully display a page. Target: less than 3 seconds.
18. Mobile-First
Approach where Google primarily indexes the mobile version of your site.
Security and Technical
19. HTTPS
Secure protocol with SSL certificate. Mandatory for good SEO.
20. Nofollow
Attribute telling search engines not to follow a link or pass "SEO value" to it.
Types of SEO
21. On-Page Optimization
Optimizations done directly on pages: content, tags, structure.
22. Off-Page Optimization
Actions external to the site: link building, social media, mentions.
23. Local SEO
Optimization for geographically targeted searches. Essential for physical businesses.
24. Technical SEO
Infrastructure optimizations: speed, crawlability, architecture.
25. International SEO
Optimization for multiple countries/languages with hreflang tags.
Algorithms and Practices
26. Google Algorithms
Formulas determining page rankings. Frequent updates (Core Updates, Helpful Content, etc.).
27. RankBrain
AI component of Google's algorithm interpreting complex queries.
28. Black Hat SEO
Techniques not conforming to Google guidelines. Risk of penalties.
29. White Hat SEO
Techniques respecting Google's rules. Sustainable strategy.
30. Grey Hat SEO
Techniques on the edge of guidelines. Risky long-term.
Advanced Concepts
31. Search Intent
What the user is actually looking for:
- Informational: learn something
- Navigational: find a specific site
- Transactional: buy
- Commercial: compare before buying
32. Penalties
Google sanctions for guideline violations. Can be algorithmic or manual.
33. Conversion Rate
Percentage of visitors completing the desired action (purchase, signup, etc.).
34. SEO Audit
Complete analysis of a site's SEO health to identify issues and opportunities.
35. EEAT
Google quality criteria:
- Experience: author's experience
- Expertise: expertise on the subject
- Authoritativeness: recognized authority
- Trustworthiness: reliability
SEO in the Age of AI
Search engines write answers now, on top of listing links. AI Overviews launched in the US back in May 2024, so if you search in English you've already had 2 years of them. Four terms to know.
36. AI Overviews
Google's AI-written summaries, parked above everything else in the results (SGE was the old name). They answer the question on the spot, and plenty of readers never scroll past them. Pew Research tracked the browsing of 900 US adults through March 2025 and found they clicked a regular search result on 8% of the pages that showed an AI summary, against 15% on the pages that didn't. Links inside the summary itself got clicked 1% of the time.
Google says AI Overviews now run in more than 200 countries and 40+ languages. To get pulled into one, write plainly and answer the question early on the page, because that's the text a model can quote without having to interpret it.
37. GEO (Generative Engine Optimization)
Getting cited by generative engines: AI Overviews, ChatGPT, Perplexity, Copilot. The work looks a lot like classic SEO with a different finish line, since you're chasing the citation the model names out loud in its answer.
Google's line is that there's nothing separate to do. Its documentation says there are "no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary". Agencies selling GEO retainers tell a different story, loudly.
38. AEO (Answer Engine Optimization)
The older cousin, pointed at answer engines. You structure your content as clean questions and answers so an assistant can lift a block of it whole. A tidy FAQ and definitions that get to the point carry most of the weight.
Where AEO stops and GEO starts is genuinely disputed. Some people treat AEO as the broad parent (featured snippets, voice assistants, anything that returns a direct answer), others use both words for the same job. As of early 2026 no consensus definition exists in the academic literature either. Pick whichever term you like and get on with the writing.
39. llms.txt
A proposed file, robots.txt style, meant to point AI models at a clean readable version of your content. Adoption stalled. Gary Illyes said in July 2025 that Google doesn't support it and isn't planning to, and John Mueller called it "purely speculative" again in June 2026, comparing it to the old keywords meta tag. Ahrefs checked 137,210 domains in May 2026 and found 97% of published llms.txt files had received zero requests.
I still keep one on this site, because a script generates it in a second and Ahrefs' own read is that it works as reference material for coding agents. As a search lever in 2026, it does nothing.
Conclusion
Knowing this vocabulary is the first step to following what actually happens under the hood of your rankings. SEO moves fast, AI is shaking it hard right now, but the fundamentals above still hold.
On a Shopify store, a good chunk of SEO plays out in the technical layer: speed, crawlability, a clean structure. That's exactly what I go through in my audit, with a concrete action plan at the end. You can also see the kind of projects I deliver in my portfolio section.
Need help with your SEO strategy? Contact me for personalized support.
