Is used to to summarize the content of a webpage. This summarization is usually shown below the pages
<title>-tag in search engines.
<meta name="description" content="JokeNetworks Docs for WHATWG MetaExtensions">
content should be <165 characters, since search engines (e.g. Google) are typically showing only this amount of characters.
In the WHATWG WikiUp to date: v2.3.3