SEO Website Optimization: word frequency and density
 

Keyword density is the key words the total number of words divided by number of visible page text, or keyword density is the normalized term frequency.
In fact, keyword density in search engine algorithms is a less relevant concept, observed ranking in the previous page, we will find that both the density as low as 1% or 2% of the pages, to 20%page. Nature writing and the page will inevitably be several keywords, which have been completed to optimize.