Keyword
A keyword is the word or phrase a user types into a search engine. In SEO and SEM, keywords are the queries you optimise pages for, and the unit by which search volume and rankings are measured.
Keywords as the unit of search
Everything in search is measured per keyword: a page ranks for a keyword, a query has a search volume, and difficulty is judged per keyword. Choosing the right keywords is the foundation of any SEO or content strategy.
Types of keyword
Short "head" keywords are broad and competitive; long-tail keywords are specific, lower-volume and easier to win. Keywords also differ by intent — informational, navigational, commercial or transactional — which should match the page you point at them.
Keyword data from Kwinside
The Kwinside keyword API turns a seed keyword into a list of related keywords and their search volumes across six languages.