Comments on meta keywords tags and SEO

The most important thing about the meta description is that it shows up with your site title in the actual search listings. This is the same with your page title. So human eyes will see it, and will be trying to decide whether to click on your listing or someone else's. Write a good title and meta description and you can improve your chances of getting click throughs from actual people.

well whoever answers this question please tell me what are search spiders.... and how do we use them to assist in SEO

Search spiders are the little bots that the search engines send around the web to find content. They way you can assist them is to make sure they can get to your pages - make sure all your links are crawl-able (they're not in flash or something), your pages are accessible (no 404 errors and such, or orphaned pages), and that your site has a good navigation structure. Inbound links from other sites also help the bots to find you, and the more & better links you have the more often the spider will visit your site.

For more, read the section on technical guidelines in the Google Webmaster Guidelines:

http://www.google.com/support/webmasters/bin/answer.py?answer=35769