In general, "amount data" refers to numerical data that represents a quantity, such as a dollar amount, a weight, or a quantity of items. In the context of financial data or accounting, "amount data" usually refers specifically to the monetary value of a transaction or a balance in an account.
XML validation handles complex data relationships and structures by using XML schema definitions, such as XSD, which provide a structure for defining the elements, attributes, and relationships in an XML document. The XSD defines the constraints and rules for the data that can be stored in an XML document, such as data types, values, and ranges. When an XML document is validated against an XSD, the validation process checks if the document follows the rules and constraints defined in the XSD. If there are any violations or errors, the validation process will return an error message indicating where the problem lies, allowing the data to be corrected before it is stored or transferred. This helps ensure the data integrity and quality of the XML document.