Not all search engines use meta tags anymore. However, some still do, especially AltaVista and other older search engines used them to help determine a site's theme and relevance to a given term. So it's still a good idea to add them to your website. There are extra meta tags you can also use but most are not necessary or important for the search engines to get. Don't forget that your page title is very important. I recommend to try to include your top keyword phrase or keywords.