If you want to understand whether Google does or does not use the keywords meta tag in web ranking then the best person to learn from is Matt Cutts. Matt is Head of Google’s Webspam Team and in this video he explains Google do not use the meta keywords for rankings.

If you listen to what Matt has said here you can help to optimise your website yourself.

This page was Google Webmaster Help – Google does not use the keywords meta tag in web ranking