Welcome to the SEOTT SEO encyclopedia: 63 plain-English entries covering every part of search engine optimisation, from how Google crawls a page to how AI assistants choose which brands to cite. It is the reference library behind our SEO tips and tricks, written for business owners, marketers and anyone learning SEO.
New to the subject? Start with what SEO is, then read the four pillar guides on technical, on-page, off-page and AI search. Each entry links to its pillar and to closely related terms, so you can follow a topic as deep as you need.
SEO basics
- What is SEO: the practice of earning free traffic from search engines.
- SEO expert: the specialist who plans and runs search optimisation.
- Organic SEO: growing unpaid search visibility.
- White hat SEO: tactics that follow search engine guidelines.
- Black hat SEO: tactics that break the rules and risk penalties.
- SERP: the search engine results page.
- SEO vs PPC: organic rankings compared with paid ads.
- Google algorithm updates: core, spam and other ranking changes.
Technical SEO
- Technical SEO: the pillar guide to crawling, indexing and site health.
- Crawling and indexing: how Google discovers and stores pages.
- Robots.txt: the file that controls crawler access.
- XML sitemap: a list of URLs you want indexed.
- Canonical tag: the preferred version of duplicate pages.
- Noindex tag: keeping pages out of search results.
- Duplicate content: the same content at several URLs.
- HTTP status codes: 200, 301, 404, 5xx and what they mean.
- 301 redirect: a permanent move from one URL to another.
- Core Web Vitals: LCP, INP and CLS speed metrics.
- Mobile-first indexing: Google ranking the mobile version of pages.
- Schema markup: structured data for rich results.
- Hreflang: targeting languages and countries.
- JavaScript SEO: making JS frameworks indexable.
- Crawl budget: how much of a site Google crawls.
- Site architecture: structuring pages and navigation.
- Orphan pages: pages with no internal links.
On-page SEO
- On-page SEO: the pillar guide to optimising each page.
- Search intent: the goal behind a query.
- Title tag: the headline shown in search results.
- Meta description: the snippet below the title.
- Header tags: H1 to H6 headings.
- URL structure: clean, readable web addresses.
- Image alt text: describing images for SEO and accessibility.
- Internal linking: links between your own pages.
- Anchor text: the clickable words in a link.
- Keyword cannibalisation: your pages competing with each other.
- Featured snippets: the answer box at position zero.
- E-E-A-T: experience, expertise, authority and trust.
Content and keywords
- Keyword research: the pillar guide to finding what people search.
- Long-tail keywords: specific searches with clear intent.
- Keyword difficulty: how hard a term is to rank for.
- Semantic SEO: optimising for topics and entities.
- SEO content writing: writing pages that rank and convert.
- Topical authority: becoming the go-to site on a subject.
- Content decay: why old pages lose traffic.
Off-page SEO and links
- Off-page SEO: the pillar guide to authority signals.
- Link building: earning links from other websites.
- Backlinks: links from other sites to yours.
- Nofollow links: dofollow, nofollow, sponsored and ugc.
- Domain authority: third-party link strength scores.
- Guest posting: writing for other sites.
- Digital PR: earning press coverage and links.
- Toxic backlinks and disavow: when to ask Google to ignore links.
Local and ecommerce SEO
- Local SEO: the pillar guide to the map pack.
- Google Business Profile: your free Google Maps listing.
- NAP citations: consistent business details online.
- Online reviews: how reviews affect rankings.
- Ecommerce SEO: ranking product and category pages.
AI search
- Generative engine optimisation (GEO): the pillar guide to being cited by AI.
- AI Overviews: Google’s AI-generated summaries.
- Answer engine optimisation (AEO): becoming the direct answer.
Measurement and tools
- Google Search Console: Google’s free performance tool.
- SEO audit: a step-by-step site review.
- SEO KPIs: the metrics that prove SEO works.
How to use this encyclopedia
Each entry answers one question in depth, with examples, checklists and FAQs. If you are planning a project, read the pillar for that area first, then the entries it links to. If you are fixing a specific problem, jump straight to the term.
Need hands-on help?
If you would rather have someone do the work, read our guide on how to hire the right SEO expert, or contact SEOTT.