Sitemap

A sitemap helps search engines index your pages easier and more thoroughly, improving visibility. However, Google recently stated that HTML sitemaps aren't “useful” for SEO.

A sitemap file can only reference files that reside in the directory of the sitemap file or its subdirectories.
<?xml version="1.0" encoding="UTF-8"?><urlset
     xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
   <loc>http://www.mysite.com/</loc>
   <lastmod>2014-08-22</lastmod>
   <changefreq>daily</changefreq>
   <priority>0.5</priority>
  </url>
  <url>
   <loc>
      http://www.mysite.com/product?id=45&amp
    </loc>
   <changefreq>monthly</changefreq>
  </url>
  <url></urlset>

<urlset> references the protocol standard.

<url> signifies a URL entry.

<loc> specifies the location.

<lastmod> specifies the date on which the file was last modified. It has the format YYYY-MM-DD.

<changefreq> specifies how frequent the page probably changes. It can be ‘always’, ‘hourly’, ‘daily’, ‘weekly’, ‘monthly’, ‘yearly’, andnever’.

<priority> specifies the importance of this URL relative to the others of the same site. It ranges from 0.0 to 1.0.

The priority assigned to a page via the sitemap.xml file may influence ranking. (more in 5.6.9)