Keyword optimization is an important process for SEO. Keywords are the search queries done by the users in search engine. Most of the users search with a sentence merged with 3 or 4 keywords. In SEO these are called as key phrases and long tail keywords. These keywords are used in title tag, Meta tag of the HTML coding for the website. There are various concepts that you should know for the Keyword optimization.
Keyword Frequency in SEO: Keyword frequency is defined as the number of times a keyword is repeated in a website. Even though you can repeat the keywords in title, Meta tags but doing it with more frequency can harm your website. This will be the case of keyword stuffing.
Keyword Density in SEO: Keyword density is the percentage value of the number of keywords appearing on your webpage compared to the total number of words on the same page. As per Google, Search engines have moved out of this concept.
Keyword Prominence in SEO: Keyword prominence refers to the prominence level of your keywords with the web page. This means how close your keywords are placed such as in title tags, Meta tags, h1 tags or even in the first paragraph of your webpage.
Keyword proximity in SEO: Keyword proximity refers how close the keywords are placed to each other. It is the distance between your keywords. The close you place them the better would be the ranking in search engine. Make sure that it is meaningful for both human and search spider.