XHTML is a specification that describes how the HTML code for the pages should be generated.
This is important for:
In our effort to offer the best quality website, we test it and therefore, all pages generated are XHMTL compliant.
You can check any page with the official validator at https://validator.w3.org
For instance, to check the home page, you can click on this link XHTML valid
You will note that we got a warning because we didn't have any heading specified in the last slide.