WSDL (Web Services Description Language) describes your service and its operations - what is the service called, which methods does it offer, what kind of in parameters and return values do these methods have?
It's a description of the behavior of the service - it's functionality.
XSD (Xml Schema Definition) describes the static structure of the complex data types being exchanged by those service methods. It describes the types, their fields, any restriction on those fields (like max length or a regex pattern) and so forth.
It's a description of datatypes and thus static properties of the service - it's about data.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…