Keyword density refers to the ratio of a specific keyword to the total text on a webpage. It is a percentage that expresses how often a word or phrase appears in relation to the total words on the page.
In the past, search engine algorithms placed strong emphasis on keyword density, and pages were often ranked based on this metric. In modern SEO, it is less dominant as search engines are now capable of understanding the context of content. However, it is still important to use keywords appropriately to signal relevance without resorting to "keyword stuffing."