XML Schema training topic: Include vs Import in XML schema:
While working on xml schema sometimes we come across large content which is less readable. We can convert 1 schema doc. into parting into multiple schema docs based on functional content or size of content. Whenever we want to refer these small pieces of schema as whole, we can use import or include element within schema. The difference is with include the remote schema gets included with current schema doc. into same namespace. In other side using import the remote schema gets included with current schema doc with its own namespace (other than current schema doc's namespace).
So, whenever the remote doc's namespace is same as current doc's namepsce, use the include otherwise import.