Hi

I want to know what is the use of Google API key , presently I am working on my website SEO, is it useful API key?

They're used for Google Rankings (http://www.googlerankings.com/index.php) - but unless you already have one, you're out of luck because Google isn't giving them out anymore.

Vasily

:) :) I se this a lot, what does it mean?

You can read more about the Google SOAP API key here (http://googlerankings.com/what_is_this.html). You can check a web page's Google ranking without a SOAP API key at this new Google page rank page (http://www.googlerankings.com/prindex.php).

If you're so inclined, you can read about APIs on this Wikipedia page (http://en.wikipedia.org/wiki/Application_programming_interface), and about SOAP on this page (http://en.wikipedia.org/wiki/SOAP).

EDIT: I highly recommend if you want to track your web site's stats getting a Google account and signing up for Google Analytics (http://www.google.com/analytics/). They'll give you code to insert into the pages you want to track. Probably the best stats package out there, particularly if you're using adwords.

Vasily