Keyword Density is the number of occurrences of a key term in relation to the total content. Keyword page density is calculated by taking the number of key word occurrences, and dividing by the total number of words on a page. Page density of targeted key terms should be between 3% and 7%.
Keyword density is often calculated per tag, per section, and/or per page. As an example, the density of key terms in relation to all other text in the page title tag is extremely important. Important tags, such as the title tag and link anchor text should have a greater keyword density, even as much as 100% (without repetition). The page density, while still worthy of consideration, is less important, as long as there is adequate representation of the targeted terms.
Keyword Proximity refers to the distance in space, as measured in words, between two words or two key phrases. The proximity of a word or phrase in relation to each other and other key phrases is extremely important when determining how to use word combinations in page titles and page content. Keyword Prominence refers to the importance of a key word or key term, as measured by:
The position of the key term in relation to the rest of the text in any given position.
The density of the key word or term on a page and across an entire web site
Words and/or phrases that appear first in a title, heading, and paragraph are given a greater level of importance in ranking considerations. Managing the prominence of key words, terms and phrases is important for:
The entire web site architecture
Each page
Each title, heading, and all link anchors
The design of paragraph content