Keywords density is term which use in content for including links in site with higher expose in search engine. Generally you need to use 3 to 5 keywords density
As per my point of view keyword density is the percentage of times a keyword or phrase appear on a web page compared to the total number of words on the page...
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 as a factor in determining whether a web page is relevant to a specified keyword or keyword phrase.
Keyword Density is the amount of event of search phrases to the text in the rest of your web site.It is important for your main search phrases to have the correct keyword density to position well in Search Search engines.