What is keyword density?
Keyword Density simply means how many times a keyword is there in your content. It is calculated in percentages according to the length of your content. This concept is used in SEO. 3% keyword density is good for one-word keyword and 1-2% Keyword density is good for long tail keywords.
Keyword density is the percentage of times a keyword or phrase appears on a web page compared to the total number of words on the page. In the context of search engine optimization, keyword density can be used to determine whether a web page is relevant to a specified keyword or keyword phrase.
They are correct! Make sure not to cram keywords. It will have a negative effect on your SEO ranking.