Getting a high ranking for your website from search engines is not achieved by just adding 'Meta Tags' to the head of your web pages. Meta Tags are basically code inserted into a part of your web page which is not visible to visitors. They can influence how your web pages are described by some search engines, and can prevent pages from being indexed at all.
The most common types of meta tags you may have in your web pages include TITLE, META DESCRIPTION & META KEYWORDS.
Whatever text is in the title tag will appear in the reverse bar of someone's browser when they view the web page - the reverse bar in the Explorer Browser is the blue horizontal bar at the top. The contents of this tag also display in browser 'favourites' or 'bookmarks' when details of your site have been saved by somebody. The text you use in this TITLE tag is in fact, a critical factor in deciding how a search engine will rank your web page. Its contents will also display in the listings of 'crawler' search engines.
You can influence the description of your web pages by some crawler search engines, if you use the META DESCRIPTION tag.
Google however will actually ignore this tag, and will generate its own description for a page.
Most crawler search engines now ignore the META KEYWORDS tag. It's main use at the moment is allowing you to provide extra text to your pages for search engines to index. The text in the META KEYWORDS tag should also be mentioned in the text of the page below to make it useful for some crawler search engines. Using the same keywords too often in the META KEYWORD tag can damage your web pages chances of ranking well in the search engines.