What exactly is a sitemap.xml file?
“Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL…” http://www.sitemaps.org
Sitemaps allow us to include additional information about each URL or page on your website, such as when the page was last updated, how often the page changes, and how important the page is in relation to other pages on your website. These modification notifications enable search engines to crawl the site more intelligently – only crawling pages that need to be refreshed or added in their database. This minimizes the traffic on their servers and yours. Less traffic means using less data bandwidth, lowering costs for both you and them.
Search engine XML sitemaps supplement the existing search engine crawlers that search engines use to discover new web pages. By implementing the xml sitemap in conjunction with the robots.txt file, search engines’ spiders are able to find more of your pages while reducing the resources needed to index your pages.
Benefits of an XML sitemap
Rand Fishkin, of SEOmoz, offer the following advice on Google XML sitemaps (http://www.seomoz.org/b2b-blog/expert-advice-on-google-sitemaps-verify-but-dont-submit):
“Without sitemaps, a search engine visits your site’s pages through links on and off the site, indexing and ranking those pages it deems worthy of being indexed and ranked.
When a search engine crawls your site and fails to index particular pages, you have a signal from the engines that those pages lack the necessary components for inclusion, be they architectural, link strength, content-related, etc.
Sitemaps enables search engine to crawl and index pages that they might not ordinarily include in a normal crawl process.
If a page lacks the link juice, internally or externally, or has content that engines wouldn’t normally deem worthy of indexing, Sitemaps may overlook these weaknesses and include those pages in their indices.”
There is an optional tag in the sitemap for the priority of the page. This indicates to the search engines how important a given page is relevant to all the others on your site. The search engines can then order the crawling of your website based on priority information.
Submitting your XML sitemap to the Search Engines
Your XML sitemap can and should be submitted to Google, Bing, Yahoo and other search engines to help them crawl your website better. There are many more key benefits when using a Sitemap in conjunction with Google Webmaster Tools.and Bing Webmaster Tools. You can submit your XML sitemap to both tools, and after about 24 hours you’ll be able to see your website search term stats, crawl statistics, listing errors, html suggestions and more. It’s a great tool that every website owner should be utilizing for each website they own / manage.
You can also create multiple sitemaps for your website. Common “themed” sitemaps are for images, videos, PDF and other specifics assets. Or, you can break you sitemap up into the sections of your website. You could also create sitemaps for mobile, news and press releases. When you have created all the sitemaps, you should refereme them in your robots.txt file.
There are many XML sitemap generators out there. However, it is my utmost recommendation that you work with your CMS and your website provider to create dynamic XML sitemaps, that update your XML file whenever a change it made to the website.