Search engines and people (indirectly) use meta tags.
Are meta tags necessary? Each search engine places its own importance on meta tags. Google never discloses how it utilizes them. There are a good many sites that achieve page one ranking on Google that use no keyword or description tags at all, so take it with a grain of salt when someone tells you they are really essential for Search Engine Optimization. Each search engine has its own method for indexing — some assign meta tags considerable importance, thus it is best not to omit them.
Meta tags are lines of code that are hidden in web pages. The code information is not revealed in the web browser (but refer to the discussion of the description tag, below) but they are utilized by search engines to help categorize your web content. It is possible that you might choose to omit descriptions, or keywords, but your site won’t look right if you don’t put a “title” tag, since the web browsers will show it as “Untitled”.
In the past, people would insert useless or repetitive information in their meta tags, trying to receive more traffic. So to stop people from cheating, not a lot of weight is assigned to a meta tag’s keywords these days; however, they are still checked for relevance. You will not be ranked well at all if you stuff them with keywords that do not pertain to your page.
The “head” section of a web page is where meta tags are found. Some people suggest using only lowercase letters in your tags, and avoid repeating terms within the keyword tag.
Mostly, the real meta tag contents are not visible, but the “description” meta tag’s information will be shown on nearly all of the search engine results as well as the title page when the results are revealed. Avoid repetition of keywords in the description tag, and keep the description text relevant.