Meta tags are hidden HTML tags used to describe various aspects about a Web page. The two most important meta tags are the meta description and meta keywords tags. Let's take a closer look at each meta tag.
Meta description tags

The contents of meta description tags are indexed by some search engines as the page description in its search engine results.
However, meta description tags is often misused, with misleading or even false descriptions about a page. As a result, the relevancy of search results are often compromised, so search engines have begun to de-emphasize the importance and even totally ignore the contents of the tag.
Some search engines, such as AltaVista and Inktomi, do still index the contents of a meta description tag for its search results. But if the meta description tag is missing, the search engine will usually extract a description from the body text. The description should be able to sell the page.

Meta keywords tags
The contents of a meta keyword tag is used to help define the important keywords of a page. It sounds good in theory. However, in practice, the meta keywords tag is often misused, including the addition of excessive or irrelevant keywords. So much so, that most, but not all, search engines totally ignore the contents of the meta keywords tag.

Inktomi is one of a few search engine that indexes the meta keywords tag. Since Inktomi provides search results for top search engines such as MSN, HotBot, and Overture, it's worth the effort to include the meta keywords tag in your Web pages.

If you do decide to use the meta keywords tag, include the most important keyword phrase in the content of the tag. The meta keywords tag should be placed just after the meta description tag.