Keyword Proximity, Keyword Prominence

Keyword Proximity, Keyword Prominence
Keyword Effectiveness Index
According to KEI, it is efficient to optimize for keywords that have huge amount of searchers, but only a few competing pages, to analyze the strength of keyword.
KEI = Popularity ^2/ Competitiveness
Popularity - number of searches for a keyword (for example, a Word tracker estimates),
Competitiveness - number of search results in search engines (for example in Google) using exact match for a keyword.

Keyword proximity refers to how close are keywords to each other. Using “stop words”, such as “the”, “and”, “or” (every language have different stop words) is simply breaking the keywords importance. You should never break your most important keywords as search engines calculate keyword proximity and give value to it.

Keyword Prominence:
Keyword prominence refers to how close to start of websites code a keyword is located. The keyword located closer to the beginning of text is given more importance than following keywords.

Spider:
This program downloads web pages just like a web browser. The difference is that a browser displays the information presented on each page (text, graphics, etc.) while a spider does not have any visual components and works directly with the underlying HTML code of the page. You may already know that there is an option in standard web browsers to view source HTML code.

Crawler. This program finds all links on each page. Its task is to determine where the spider should go either by evaluating the links or according to a predefined list of addresses. The crawler follows these links and tries to find documents not already known to the search engine

Indexer. This component parses each page and analyzes the various elements, such as text, headers, structural or stylistic features, special HTML tags, etc.

Database. This is the storage area for the data that the search engine downloads and analyzes. Sometimes it is called the index of the search engine.

Results Engine. The results engine ranks pages. It determines which pages best match a user's query and in what order the pages should be listed. This is done according to the ranking algorithms of the search engine.

Web server. The search engine web server usually contains a HTML page with an input field where the user can specify the search query he or she is interested in. The web server is also responsible for displaying search results to the user in the form of an HTML page.