Meta tags, or more correctly meta elements, are structured tags used to provide information about a web page. These tags are placed in the “head” section of the html code and are not visible when viewing a webpage. The most commonly used meta tags are the meta description and meta keyword tags.
Frequently, people believe that meta tags play a significant role in obtaining a top search engine ranking. In reality, they do not, but they are important in other ways. Since meta tags are not visible when viewing a web page, they become prime targets for abuse, or spam. There is nothing to keep a web developer from irrelevant keywords in the meta keywords tag, or writing a meta description that does not accurately reflect the contents of the page. As a result, search engines place very little importance on meta tag data when determining search engine ranking positions.
But there are important reasons for including effective meta tag data, especially in the meta description tag. Search engines typically title tag as the headline of a search result and the meta description data as the search engine results description. So a well meta description should entice people to click on your search engine listing. It should be relevant to the content of that specific page, and not the same on all pages. A good meta description could easily make the between someone clicking on your search result vs. another one. So write the meta description as if it’s the only chance you will have to get a potential client to visit your site, because it may be.
As for meta keywords, they are of little value. Their most significant feature is that they can get you in trouble if you include keywords that are not relevant to your page or if you include dozens of keywords not found on the page. Meta keywords were one of the original sources of spam, so search engines learned to ignore them. My recommendation is to use no more that six to ten meta keywords, and to make sure that they are relevant. Abusing the meta keyword tag may get you noticed by the search engines, for the wrong reasons. Abuse may cause your page to be ranked lower, or to get dropped from the rankings altogether.