What is the difference between XML and XSD?

Question

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

Answer 1

Basically an XSD file defines how the XML file is going to look like. It's a Schema file which defines the structure of the XML file. So it specifies what the possible fields are and what size they are going to be.

An XML file is an instance of XSD as it uses the rules defined in the XSD.