If you're new to web development and search engine optimization, you may find this tool useful to ensure your Meta Tags are correctly formed. The tool has two fields -- Keywords and Description:
Keywords: Enter a short list of keywords and terms related to your site. The terms can be separated by a comma, but a delimiter is not required.
Description: Enter a brief description about your site and what it offers. This is sometimes used by search engines as a website’s 'snippet' for search results.
At one point Meta tags where a considered a relatively important factor by search engines. AltaVista and other older search engines used them to help determine a site's theme and relevance to a given term. This is no longer the case. Search engines now rely on more advanced techniques to do this. Meta tags still have some life left in them; they are sometimes used as the snippet of a site's content in search engines result pages by Google and possibly by other search engines. It's also possible they still have some influence with some search engines in determining a site’s content.