An XML sitemap is a fairly simple XML file that contains information about one or more URLs on your Web site. The information that is stored there helps search engines better spider your site. All it needs to be is a list of URLs for your Web site, but to get more out of it, you want to include other information as well For more info: please check http://webdesign.about.com/od/sitemaps/a/aa010807.htm
every site requires a site map, and it is very important to have because the crawling of the search engine is based on such sitemaps and ranking is given accordingly.
Not Totally Agree with UNANI sorry, One of the pointing to google, with usage of xml file of sitemap they are getting and provide back few impotent reports through webmastersTools. Sitemap is important but not all the time.
A sitemap is really only important if you have many pages that you want crawled and indexed by google. It basically just tells google "hey I have these pages you should check them out" Its more an SEO thing.
Site map is the total amount of contents listed. its important to have. because site map tells the Search engines that what kind of content you have.
A sitemap helps the search engine spiders to find your web pages and index them . It gives them information about every page on your site and enables spiders to crawl only the new or updated pages that they need to add to their database in order to keep information up to date for users. This reduced crawling time on both their servers and yours means using less bandwidth and less costs. For the human visitors to your site, the sitemap tells them exactly what you have on your site and helps them find things easily.
Site map is one of the most significant pages of any website that contains link to all important pages. And simply put if any link is not working we can get on the site map and the broken links can be easily identified.
Have noticed that since you have been on this forum most of your question are 'what is' or 'what are' type of question,i am coming to the conclusion that you are just post building,you are trying to make out that you are a novice but you do infact have the knowledge to ask these type of questions.In the future why dont you do a google search on these new 'buzz' words you are using rather than asking all the time. That is what google search is for after all.
Sitemap helps the search engines locate those pages of your site that their search engines missed, and gives an overall structure to your site
XML sitemap helps to crawl up the whole website quite easily so that gives a better advantage for your site.
XML sitemap helps in easy crawling of web pages. It’s more important to have an XML sitemap in website, when you have a website with number of pages.
search engines like Google use xml sitemaps while they indexed pages. Thats why every webmaster use xml sitemap for their website to get indexed fast on Google.