What Is a Keyword? Definition for SEO
A search term or phrase that a web page is optimized for.
What is a keyword?
A keyword is a search term that people type into a search engine. Keywords are the basis of every SEO strategy, because they show what your target audience is looking for.
Example: someone in Zurich searches for "SEO agency Zurich". For an agency, that phrase is a keyword worth optimizing a page for, because it matches what the agency offers and where it is based.
Types of keywords
- Short-tail – 1-2 words, high volume, strong competition (e.g. "SEO")
- Long-tail – 3 or more words, less volume, higher conversion (e.g. "SEO agency Zurich")
- Transactional – intent to buy (e.g. "book SEO agency")
- Informational – looking for knowledge (e.g. "What is GEO?")
If several pages on your site target the same keyword, they can get in each other's way. That problem is called keyword cannibalization.
Keywords and AI optimization
For LLMO and GEO, the focus shifts: instead of single keywords, entities and topic areas become more important. AI models understand context and relationships, so optimization has to cover the whole topic rather than single search terms. Our article on content formats for AI search shows what this looks like in practice.
Frequently asked questions
What is a keyword?
A keyword is a search term that people type into a search engine. Keywords show what your target audience is looking for and form the basis of every SEO strategy.
Why do keywords matter for SEO?
Keywords tell you which queries a page should be found for. For AI search, entities and topic areas become more important than single keywords, because AI models understand context.
What is an example of a keyword?
"SEO" is a short-tail keyword with high volume and strong competition. "SEO agency Zurich" is a long-tail keyword with less volume but a higher chance of conversion.