The structure of an XML document is defined by the DTD (Document Type Declaration), which specifies which elements and attributes are allowed. It can be defined inline or as an external reference within an XML document.
- When a DTD is stated within the file, it is referred to as an internal DTD declaration.
- When a DTD is stated in a separate file, it is referred to as an external DTD declaration.
The following are some of the benefits of DTD:
- It offers a map of how to validate the XML document to validating parsers.
- It allows you to design your own XML file format, allowing users and developers to comprehend the data structure.