But, as the consumers of these files, how can we differentiate between them? An XML namespace allows us to qualify an element in the same way as telephone area codes qualify phone numbers.
There might be thousands of telephone numbers of 545-321.
Where HTML was designed to display data and specify how that data should look, XML was designed to describe and structure data.
In this way, an XML file itself doesn’t actually do anything.
This is our hierarchy, and will be important later, when we need to parse the document.
For example, take the following XML files, both of which describe some data: The first file specifies genres of movies, while the second specifies different types of camera film.This is important — it means that other systems can interpret your XML, which is not as easily achievable in plain text.This describes what is meant by "interoperable file format" — once you produce an XML file, it is open to everyone.This standardises exactly how your XML file is formed so that other systems can understand it.For example, XML 1.0 requires that all XML files consist of one root element; that is, a single element contains all other elements.