<meta name="description" content="">
short description of the page – not more than 150 characters (for snippet) – the most important info – closer to the beginning
<title>The Title of the Page</title>
generally shown as the title in search results, and as the page title – not more then 60 characters. Use keyword (better the same to use in H1)
<meta name="robots" content="" />
noindex: prevents the page from being indexed
nofollow: prevents the Googlebot from following links from this page
nosnippet: prevents a snippet from being shown in the search results
noarchive: prevents Google from showing theCached link for a page
unavailable_after:[date]: lets you specify the exact time and date you want to stop crawling and indexing of this page
noimageindex: lets you specify that you do not want your page to appear as the referring page for an image that appears in Google search results
none: is equivalent to noindex, nofollow
Meta tag <keywords> is not used by Google since 2009 already!
Some people, who are not much pointy-head to the subject still spending much time setting meta keywords.
This video from Google is for them