Therefor Validating XML is very important part in programming.
In maximum cases We are unaware about the depth, type of nodes or type of element contents of a XML document.
In such cases we have to check each node before reading for the information. So if we do Validating XML documents, we can reduce lot of burden from our code.
Without use of validation, its quite a bit tedious to code and debug.
Before parsing XML document in java or any other language program, we can check for the validity of the XML file.