Definition: the location (i.e. placement) of a given keyword in the HTML source code of a web page. The higher up in the page a particular word is, the more prominent it is and thus the more weight that word is assigned by the search engine when that word matches a keyword search done by a search engine user. Consequently, it’s best to have your first paragraph be chock full of important keywords rather than superfluous marketingspeak. This concept also applies to the location of important keywords within individual HTML tags, such as heading tags, title tags, or hyperlink text. So get in the habit of starting off your title tags with a good keyword rather than “Welcome to.
FirstClickSEO Commentary: If you want to gain good rankings for a particular keyphrase, check out where it is mentioned, not just how often.