QUOTE(C.Rebecca @ Jul 26 2011, 10:02 AM)
Can you please explain how closeness affect the optimization of the page. I really have no idea about this.
Keyword proximity refers to the closeness between two or more keywords. In general, the closer the keywords are, the better.
How Keyword Density Affects Search Engine Rankings
How Keyword Density Affects Rankings In Search Engine
Using the example above, if someone searched for "search engine rankings," a web page containing the first sentence is more likely to rank higher than the second.
The reason is because the keywords are placed closer together. This is assuming that everything else is equal, of course.
I hop it will helpful you for the batter understand.