The meta tag generator has two sections: one for keywords and one for description.
Meta tag section for keywords:
Here you list a number of keywords and terms that describe the content of your site. You can separate the keywords with a comma.
Meta tag section for description:
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.
Meta-tags used to be a really important part of search engine optimization. They helped define the these and relevance of a website. Nowadays search engines use different techniques to determine these things. Meta tags are still useful, they show up as site descriptions in some listings. Meta tags also still may have a place in defining the content of a site with some engines.