An XML sitemap is a file that lists all the URLs of a site. It also includes secondary information, such as when a page has been updated, its update frequency, and relative importance. With all its attributes, the annotation for each URL in the XML sitemap would be:
<?xml version=”1.0″ encoding=”UTF-8″?>
Keep in mind that hreflang links could also be included in the XML sitemap, as we discussed in the multilingual SEO section.
The XML file is typically located at https://airline.com/sitemap.xml or https://airline.com/sitemap_index.xml. However, a sitemap can be placed anywhere on a site, considering that it will affect only descendants of the parent directory.
XML sitemaps are especially important for large websites because they help search engines discover, crawl, understand, and index the webpages. Actually, Google has said that it receives XML sitemaps “in the form of an energy drink”: