This is the ratio of a keyword or keyphrase to the total words (depth) on a page. It is one of the most critical aspects of search engine optimization. To improve search engine ranking, your keyword density must not be too high or too low.
Try to aim for a keyword density of 1% to 7%. To achieve 1% you would need to insert your keyword or keyword phrase once for every hundred words. If you only used your keyword once in one thousand words, this would result in diluting your keyword density.
Don't try to stuff all your keywords together, separated by commas. Search engines may see this as spam, penalizing your rankings.