A keyword is a word or phrase that describes content. Online keywords are used as queries for search engines or as words identifying content on websites.
When you use a search engine, you use keywords to specify what you are looking for, and the search engine returns relevant webpages. For more accurate results, try more specific keywords, such as "Blue Mustang GTO" instead of simply "Mustang". Webpages also use keywords in a meta tag (in the
<head> section) to describe page content, so search engines can better identify and organize webpages.
- Keyword on Wikipedia