Looking at the above XML document, it is not difficult to appreciate that weather reports sent in from all over the country in this form could be processed and collated by a suitable application program. But for this to work, everyone would need to agree to use the same tags to define the data elements, and possibly to agree that they will start with the date and time, and follow this with information about where it comes from before giving the weather details themselves. In other words, users must agree to a "standard” for their weather report documents or files for it to be possible to develop a computer application to process them. Such an XML standard is known as a schema, and describes the possible data content of an XML document in a rigorous and formal way.
A constant for any XML document is that it must be hierarchical in structure. So an XML schema is often presented like a hierarchical family tree, showing how the elements are related, and then each specific element is defined in detail. But in the incestuous world of XML, such a definition is am document itself, of course, and is usually presented as an XML document in its own right with the suffix "xsd” for XML Schema Definition.
Article ID: 1862 Created On: Tue, Jul 10, 2012 at 1:37 PM Last Updated On: Thu, Jun 22, 2023 at 4:42 PM