Difference between keyword density and keyword proximity

I want to know that what is the difference between keyword density and keyword proximity. What are the importance of these two in the promotion of website.

Sorry, but this is far too vague a question, as a simple search would have sufficed to answer the question. Please search (both the forums and via your favorite search engine), and if you’ve still got SPECIFIC questions, please feel free to repost.

In the meantime, THREAD CLOSED.