What is a meta description tag?
The “meta tags” form part of the html markup on your web page, however they are not a necessary part of your web pages structure. The “meta tags” are used to pass basic information from your page to another page should it be requested.
Google, Bing and Yahoo access the meta description tag on your page and use it as a description of your web page on their search engines. The description is placed under your web pages URL on the search engine. Google, Bing and Yahoo also highlight any words in your description that form part of the search phrase.
The description meta tag is probably the most used tag, the tag is used by the major search engines as a brief description of your web page. The maximum amount of characters that can be used in the description meta tag is 150, more can be used but they may be not shown.
Some web page designers omit the the description meta tag, it may not improve your websites ranking, but it can give a clear concise description of your web page on the major search engines. The description on the search engine is what your potential visitors will see.
By not adding the Meta Tag Description the search engines will take information from your site which you have no control over (top picture), however by adding the details to the Meta Tag Description you will be able to make sure that the potential visitors have a better idea what the page is about.