What is the difference between XML and XSD?

Question

What is the difference between Extensible Markup Language (XML) and XML Schema (XSD)?

Answer 1

XML versus XSD

XML defines the syntax of elements and attributes for structuring data in a well-formed document.

XSD (aka XML Schema), like DTD before, powers the eXtensibility in XML by enabling the user to define the vocabulary and grammar of the elements and attributes in a valid XML document.