Hello
The keyword density is a percentage of a keyword or phrase on a web page, compared to the total number of words on the page. Search engine optimization can be used as a factor in determining keyword density as to whether a web page is relevant to a specific keyword or keyword phrase.
For example: If a keyword appears 100 times in the text three times, the keyword density will be 3%. From a search engine's perspective, a high keyword density search engine is a good indicator of spam.
Hope it helps you