Meta tags make it possible for search engines to find your Web pages. The information we put on the page is content. Meta data is information that describes that content. Meta tags do not affect how a page looks on a Web browser.
Meta tags look like regular HTML tags.
Web policies, standards, services, and resources. Since search engines use a limited number of characters in the descrtiptions they generate, you should resist the temptation to write long meta descriptions. A sentence of 25 words that accurately summarizes the content of your page will produce better search results that long or exhaustive descriptions. Keywords in meta tags should be lowercase keywords since this is how most users enter search terms. Not all search engines make use of meta tags, and those that do only search for some attributes.