Those who work in the field of 'optimization and placement on search engines (SEO) has certainly found, increasingly, in front of the need to create a site map to facilitate crawling by search engines. Sometimes the maps are written in "simple HTML", in most cases is used to format now known as the Sitemap format.

Initially grew out of Google labs, this format is now a standard adopted by major search engines. Ma, per un motivo o per l'altro. But for one reason or another, its creation and its use are not clear at all.

Just as the mere Sitemap Sitemap XML is also a list of links. Introduced by Google with the Google Sitemaps, and then also used by Yahoo! and MSN, allows webmasters to mention in an XML file, and beyond, all the URLs of pages on a particular website you want to submit to search engine. In questo modo anche i siti dinamici possono fornire URL corretti permettendo una indicizzazione più intelligente. In this way, even dynamic sites can provide correct URLs allowing a more intelligent indexing.

The protocol is regulated by the Attribution-ShareAlike Creative Commons License who has made it possible to use also other search engines.