Meta tags are HTML
elements that allow you to specify metadata (information about what
makes up your document) within an HTML file. There are many kinds of
metadata, some of which can help search engines index your documents
more accurately.
Meta tags belong within the <HEAD>
section of a document. They do not take a closing </META> tag and you
can use many meta tags within a single document. In addition,
metatags can also specify a brief description of your document
including the document author and language, page redirection, page
titles, page descriptions, and more.
Here are some sites so you can learn more about
Metatags: