XML Sitemaps are files in XML format that are created specifically for the Web Bot. This is es a list of all URLs of a website that contain a 200 status code. You can compare the XML sitemap with a table of contents, which signals to the crawler which URLs should be indexed. But what is interesting for the web bot is mostly unknown to the user. By the way, the XML sitemap is not accessible via the navigation of the website. XML sitemaps also play an important role in search engine optimization. This is because this file format is used to control crawling in a targeted manner.
XML sitemaps enable search engines to completely capture and index all relevant URLs of a website. Even URLs that are suboptimally integrated into the website - and are therefore difficult to reach - can be included in the XML sitemap.
For websites with frequent changes, regular updating of the XML sitemap is very purposeful. A typical use case are e-commerce stores. Here, product detail pages and other content change on a continuous basis. The regular update of the XML sitemap gives important signals to the search engines. This can be accelerated a little by storing the current version of the XML sitemap in the Google Search Console or in the Bing Webmaster Tools.
The difference between XML sitemaps and HTML sitemaps is that XML sitemaps were developed only for search engines. An HTML sit emap is a relic from the time when es did not have sophisticated navigation. With the help of the HTML sitemap, users could, thanks to a tree diagram, understand the structure of a website. Es there are still websites that carry an HTML sitemap in the footer. Because from time to time the bot also looks here. Just like the XML sitemap, the HTML format may only list indexable URLs with status code 200.
Certain URLs should not be included in the XML sitemap.