Do you really need a sitemap.xml file on your site? Is it a necessity? Should you even care about having one for your site?
It depends.
As a general rule though, yes you should always have a sitemap.xml file for each of your sites. They help to make sure all your important pages on your site are indexed in search engines and they also help get new or existing pages indexed quicker.
What exactly is a sitemap file? It’s an XML file that webmasters directly submit to search engines and place on the root of websites so bots can read them.
Sitemap.xml files typically have the following structure:
(loc)http://steffanhaeberle.com/(/loc)
(lastmod)2010-09-15T22:31:22+00:00(/lastmod)
(changefreq)daily(/changefreq)
(priority)1.0(/priority)
There are numerous resources online for describing and explaining each of the elements in a sitemap file. I’m not going to cover them here. The bit of code above is just a sample to show what a standard sitemap.xml file includes. It’s just basic information that search engines use to help index pages.
You specifically can use a sitemap to make sure all your important pages are indexed in search engines. Also, if you have a big site with many regularly updated or new dynamic pages you can easily make sure search engines know about them by regularly updating and submitting a sitemap to search engines.
Sitemap.xml files help to tell Google how to prioritize inner pages on your website.
Myths about sitemap files:
Contrary to popular belief, having a sitemap on your website does NOT make search engines index more pages or index pages faster. Sitemaps are not a magic bullet though and many webmasters feel they are very insignificant. I personally use dynamic sitemap files that automatically update for each new page/post I create as well as automatically submitting the sitemap again to search engines.