Meta data, or your website's Meta tags, are snippets of code that tell search engines information about your website. I'll try and include the most common Meta tags it refers to, as well as some of the less common elements.
Meta data typically refers to three things:
The Meta Keywords of a website
The Meta Description of a website
The title of a website
These can be found by viewing the page source of a website (View-->source or page source. If you don't see the file menu at the top in Internet Explorer, hit alt-->f and then select view-->source).
Hit the control key, and the f key at the same time. Search for title, then keywords, and then description while you're looking at the page source to find the Meta tags. If that doesn't work, look for the words "Meta content=keywords" or "Meta content=description", and look for "
" for the title. The underused Meta Language tag can be found by looking for the words
The Meta Keywords tag refers to a series of words or "tags" (you want between 7 and 11 keywords) that describe the content at hand. This is not seen by visitors unless they view your source code, and is used solely by search engines.
The Meta Description tag is a brief description of the page at hand, and is what is displayed under a link in pages of search results. If nothing is there, Google will do its best to extract snippets of text from your page, however, it doesn't always do a very good job of this. This is why Meta descriptions are recommended.
Google places very little weight on the text within your Meta Description as a determining factor for your placement, and it is primarily just used to explain that page's content to those surfing search results.
Your Meta description should be less than 160 characters, as that is the cutoff point for nearly all search engines.
Your page's title is what you see at the top of your web browser when looking at a web page, and has more weight in search engine's minds (particularly Bing) than any other Meta tag. Your title can be as long as you want since search engines cut it off at different lengths, but make sure the first 65 characters stand alone, as this is the cut-off point for Google.
All websites also have a meta content tag, which just tells search engines you have HTML on your webpage.
There are also less commonly used Meta tags, like:
The Meta language tag tells search engines what languages to target when placing your website in search results. This is a less commonly used Meta tag.
The Meta zipcode tag tells search engines a zip code or zipcodes you're trying to target.
I hope this helps