Meta keywords and meta description are HTML meta tags. They form part of your website's header code. They don't appear on your page or post for visitors to see. ... WordPress SEO plugins make it super easy for you to add them from your WordPress admin area for each post and page on your website
A meta description is the description of, or excerpt from, a webpage that appears when that page is listed in search results. It's usually a couple of sentences long, and tells the searcher what they need to know about what the page contains and how relevant it might be to their query.