Simply put, WD is the number of times a keyword or phrase appears either on a particular web page or even throughout the entire website.

This can be in relation to the "search subject" or to the number of words (including or excluding meta tags) on any particular web page.

Need a Synonym ???

And, as with everything that happens in the search engine universe, sometimes it is relevant and sometimes it is not.

Just as important as "Keyword" density is the i-Synonym keyword density, for example.

Hotel >> Motor Inn >> Motel >> Hostel (normal Synonym)
or
Hotel >> Accommodation >> Resort ( i-Synonym)
or
The Bently Twins >> Calendar ( i-Synonym)

The first example is a straight forward Synonym, the second is what I call the i-Synonym. The i-Synonym means Internet Synonym and it means that "associated" or "related" keywords count when the search engines are doing their word density thing.

The second example contains the "related" word >> Adware >> KeyLogger

This is the i-Synonym. The words are related ONLY if you Know that they are related. This relationship is by TOPIC and not by regular expression. So, the programmers are given a list of associated i-Synonyms and told to program these into the next set of algorythms.

How do you find this information out ??

The truth is that is is VERY very hard to even Guess what the combinations are or will be because it requires Human 101

1. Yes and NO

Before I make the next statement, I am yet to see a program or website which proves me wrong on the following points.

Firstly, No SEO worth anything will give you their trade secrets for free. There are several X factors (or variables) which you and the programmers do not know. (unless you work at Google® or any other major search engine.)

2. You DO NOT KNOW...

(a) HOW the calculations were done for this program or website
(b) For which search engines the program calculations were written
(c) How often the programs algorythm is updated (I mean, what is the point of having someones theoretical calculations based on data which is 12-36 months old???)
(d) My all time favourite is The Ulterior Motive
This is where you get something which keeps you happy, even though it may be wrong, whilst the originator of the script or program cleans up the REAL results knowing the 10's of thousands of people (read dummies) are utilizing false information.

A classic example of mis-information was Viral Marketing. All the BIG boys said it was bad so none of the respectable agencies touched it, thus allowing a few people to clean up at the expense of the many. Hotmail used viral marketing and was sold for $400 Million USD to Microsoft. Read article here.