what's the purpose of this tag

Question

<meta name="Googlebot" content="nOdp" />

Answer 1

Meta descriptions are HTML attributes that provide concise explanations of the contents of web pages. Meta descriptions are commonly used on search engine result pages (SERPs) to display preview snippets for a given page.

Learn more.

http://www.w3schools.com/tags/att_meta_name.asp

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta