Keyword is a term that captures the essence of the topic of a document or website. Keywords are used  to retrieve documents or web pages in an information system, such as a catalog or a search engine. A popular form of keywords on the web are tags which are directly visible.  Keywords can consist of a word, phrase, or alphanumerical term. They are created by analyzing the document either manually with subject indexing or automatically with automatic indexing or more sophisticated methods of keyword extraction.

Keyword Density:
Keyword is a word that the user searches for when using a search engine. Keyword density is the ratio of the word that is being searched for (the keyword) against the total number of words appearing on your web page. If your keyword occurs only once in a page of one thousand words, it has a lower keyword density than a keyword that occurs ten times in a page of similar length.  If a particular keyword has a higher density on your web page, then the likelihood of your  web page obtaining a better search engine ranking increases. Keyword density is the root of search engine optimization (SEO). Website copy heavily laced with keywords can propel a website to the top of a search engine results list. A website that appears at the top of the search engine results list is a website that experiences more clicks, more traffic, and more potential customers. This makes keyword density an important consideration in web copy creation. When writing text for a website, webmasters and copywriters use the keywords  as often as possible within each page of text while still keeping the integrity of the copy intact. This very dense placing of keywords ensures that the page they are writing will show up toward the top of the search results page when the keyword is typed into a search engine.

Choosing Keywords:
Which keywords you choose will determine how well your pages do in the major search engines  which could equal a huge increase in targeted traffic to your site. You should choose different keywords for each page of your site, and you should choose keywords that are relevant and very specific to each page. Keywords  help your readers or site viewers find your site or content. What you need to do, in order to get page hits for whatever you want your viewers to read, is figure out exactly what phrases or words your readers might use in order to search for the type of information you have. But more importantly, you don’t want to use popular words that everyone would be using in their articles, because then you are competing with all the other articles and sites out there writing about the same thing. Having as unique of a niche as possible is the key to online success!

Keyword Placement:
The Title Bar is considered the most valuable piece of real estate on your web page. The search engines look here for a general "summary" of the content of your page. It's important that you use your Primary Keyword Phrase at the very beginning of the Title. It is also important to word  it so that the keyword in your title makes sense and interests searchers that are scanning the search results where your listing appears. The next spot on your web page to  include your keyword is the text header. It is the heading at the very beginning of your content area that defines the content on that page. Lastly make sure you have placed your Primary Keyword Phrase repeated times throughout the text on your page. Several other corresponding keywords should also be used repeatedly throughout your web page.