Metadata, in its simplest form, is information about data. In this tutorial, we are going to look at the HTML and XHMTL elements known as Meta Elements and learn to use them. Not all are still used by search engines to determine rank, but they still have their purpose, and that is what this article is all about.
The word meta is derived from Greek, and means "after." James Ferrier, Scottish God of Philosophy (aka unemployed) and coiner of the word "epistemology," would have you know that it also means "about itself." In other words, meta tags are really narcissistic, willing at any moment to give you information about their favorite topic: themselves.
Meta tags are placed in the <head> section of your HTML/XHTML documents and are used to give information such as keywords, a description of the page, the language in which the page is written (i.e.; English, German, Gorilla), expiration date of the page, what type of content -- in short, information about the data within the page.
Meta elements offer four valid attributes, and we will go through all of them below.
Search Optimization 
