A description tag is a Meta element meant to hold a description of the web page that it is connected to. Description tags contain the information that is displayed on a search engine results page beneath the title link, and outlines not only what is on the page, but has keywords in it that were searched for in the search query. Search engines suggest that the description tag be approximately two hundred words, but it is, in the end, up to the website creator. Description tags have some effect on search engine optimization, because the descriptions are an excellent place to integrate keywords and keyword variations. Unlike other Meta tags and Meta elements, description tags are recognized by major search engines, and used to inform the search engines of what is on the website.
When search engines such as Google or MSN require more information about a web page, these search engines will depend upon a description tag from a website to display a concise explanation of the web page content, as well as where the keywords that were searched for apply. Description tags also allow web page creators to add a more accurate description than if a search engine had to provide one based upon a scan of the content on the page. The description tag can help with search engine optimization as well.
The description tag is generally displayed on search engine results pages when certain keywords are searched for. This can effect search engine optimization, especially if the major keywords the website is targeting are in the description tag. Description tags can also affect click-through rates, because not all search engines display the tags and because the tags are too reliant on keywords. That is why it is important to have a well-crafted description tag as much as placing keywords within them.