As opposed to a simple text sitemap an XML formatted one tells (or potentially tells) a web spider what to spider and when.
The Sample XML sitemap from sitemaps.org
<?xml version="1.0" encoding="UTF-8"?> <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"> <url> <loc>http://www.example.com/</loc> <lastmod>2005-01-01</lastmod> <changefreq>monthly</changefreq> <priority>0.8 </url> </urlset>
The first three tags urlset, url and loc are required. The lastmod is optional as is the changefreq and priority. I can't really see the point of the lastmod tag as not only does it say that it might be ignored it could be determined by the web spider in any case. The frequency and priority are also not really applicable to this website and are more relevant to a larger e-commerce website where a page of products and pricing may change on a regular basis.
Overall, the XML format is not only more complex and difficult to administer it is not necassary for a site such as tempusfugit.me.uk.
XML Sitemap - February 2021