The "title" and "description" are important but the keywords meta is not really a factor in your search engine position. Keyword meta can be useful if you have adsense on your pages as it help target and display advertising related to your content.
Meta tags have lost a lot of their weight in recent years. Since meta tags do not appear as visible text to a site visitor they have been subject to misuse from unethical SEO's and webmasters and thus, the weight they are now given is extremely low. Nonetheless meta tag optimization is a part of a thorough positioning strategy.
Meta tags are important if you have the right content matching them. If not, importance is very low. Meta Tags lost their importance since crawlers improved their AI heuristics.
Meta keywords are essentially redundant for SEO reasons these days. Though some like to add them its far better to focus on other areas. The only time they might be useful is if a URL is submitted to a directory which then tries to use the meta keywords as "tags" for that link. Its rare for me to include them on a client website.
Hi Metadata is information about data. The <meta> tag provides metadata about the HTML document. Metadata will not be displayed on the page, but will be machine parsable. Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata. The <meta> tag always goes inside the head element. The metadata can be used by browsers (how to display content or reload page), search engines (keywords), or other web services. Regards
Title is Highly Importance while description is Important from user view point and keyword is no more important.
title and description both are important for any type of site, which can get your site high ranked and google friendly too. don't forget to put your targeted keywords in title, description and url too. hope you will be do your best..............
Of course meta tags make a difference. I agree with everyone else in here, that keywords are the least important. It still however have to weight in your site performance, but not enough and therefore some webmasters ignore it. SEO itself has evolved, and that's the main reason. Search engine spiders now are highly complex now, but several years ago it was a different story -- meaning even if you don't have keywords, your site will still be placed based on your page content, and se spiders can find out your most relevant keyword or topic based on your content. But your site title and description however, especially the title has a huge importance for search engine still.