Definition
Also written: SEO, organic search optimisation
Search engine optimization is the practice of making a site easier for search engines to crawl, index, understand and rank, so that pages appear for queries the business can actually serve. It covers technical access, information architecture, content quality, internal linking, authority signals and the measurement that tells you which of those moved.
The discipline splits into work that makes a page reachable and work that makes it worth reaching. The first is largely solvable — robots directives, canonicals, sitemaps, render behaviour, status codes, site speed. The second is not solvable in the same sense, because it is competitive: you are being ranked against every other page answering the same question.
Google states that optimizing for generative AI surfaces is still SEO, on the same index and the same ranking systems. That makes the technical floor here a prerequisite for every acronym further down this glossary, not a separate track.
The usual error
Where this goes wrong in practice
Treating SEO as a content-volume problem. Publishing more pages against the same intent usually splits the signal between them and gets all of them ranked lower than one consolidated page would have been.
Related terms
Generative engine optimization (GEO)
Generative engine optimization is the practice of improving how a source is used by AI systems that synthesise answers rather than list links. The term comes from a 2023 academic paper (arXiv:2311.09735, later accepted at KDD 2024) that measured how often a document’s content was reflected in a generated answer.
DefinitionAnswer engine optimization (AEO)
Answer engine optimization is structuring content so a direct answer can be lifted cleanly into a featured snippet, a People Also Ask entry, a voice response or an AI summary. It predates the current AI wave — the original concern was voice assistants — and overlaps heavily with both SEO and GEO.
DefinitionCanonical URL
A canonical URL is the address a site nominates as the authoritative version of a page when several URLs serve equivalent content. It is declared with a rel="canonical" link element, and it is a strong hint to search engines rather than a directive they are obliged to follow.
DefinitionE-E-A-T
E-E-A-T stands for experience, expertise, authoritativeness and trustworthiness — the framework Google’s human quality raters use to assess page and site quality. Google states it is not itself a ranking factor; it describes what the systems are being tuned to approximate, and it matters most on topics that affect money or wellbeing.
DefinitionBreadcrumbList schema
BreadcrumbList markup describes a page’s position in the site hierarchy as an ordered list. Google uses it to replace the raw URL in a result with a readable trail, which is one of the few rich results that still reliably renders.
DefinitionCrawl budget
Crawl budget is the number of URLs a search engine will fetch from a site in a given period, set by how much load the server can absorb and how much demand the engine has for the site’s content. It becomes a practical constraint mainly on large sites.
DefinitionFAQ schema
FAQ schema (schema.org FAQPage) marks up question-and-answer content so machines can read the pairs. It is still a valid schema type, but Google discontinued the FAQ rich result for nearly all sites starting in May 2026, with phased removal from Search Console tooling through that August.
DefinitionFeatured snippet
A featured snippet is a short extract Google promotes above the standard results to answer a query directly, drawn from a page already ranking for it. Formats include a paragraph, an ordered or unordered list, and a table, and the format Google chooses follows the shape of the query.
DefinitionGoogle Business Profile (GBP)
Google Business Profile is the free listing that makes a business eligible for the map pack and the knowledge panel in local results. It requires verification, and it requires either a physical address customers can visit or a declared service area for businesses that travel to customers.
Definitionhreflang
hreflang is an annotation that tells search engines which language and regional variant a page is intended for, so the right version is served to the right audience. Annotations must be reciprocal — every page in a set references every other, including itself.
Definition