What Are Meta Description Tags?
What are meta descriptions? What is the meta description tag?
Though meta description tags are not a major factor search engines consider when ranking sites, they should not be left off the page. Both the meta keywords tag and the meta description tag contribute to your search engine ranking, and the meta description tag influences the liklihood that a person will actually click on the search engine results page and visit your site.
The meta description tag is intented to be a brief and concise summary of your page's content. Think of the Yahoo! directory. You see your site title followed by a brief description of your site or business. The meta description tag is designed to provide a brief description of your site which can be used by search engines or directories. The meta description tag takes the following form:
<meta name="description" content="Brief description of the contents of your page.">
When you write a meta description tag, you should limit it to 170 characters or 200 characters at most. You should pick a style and be consistent throughout your pages, writing a unique description for each page of your site. The Open Directory (DMOZ) also a detailed guide to writing descriptions. Click here to learn about the DMOZ style. The key is that you want your description to adhere to W3C standards and be relevant to the content of the page. Again, it is intended to provide a brief summary of the contents of the page.
Search engine optimization and the meta description tag.
In addition to this article, this site is a wealth of information about meta descriptions.
For more technical information about meta tags, visit The global structure of an HTML document - W3C Recommendation. Also see Performance, Implementation, and Design Notes - W3C Recommendation.