Basic information about xsd's and namespace

An xsd file can refer to another xsd file in two ways..

• using <import> tags
• using <include> tags

The <import> tag has to be used, when an xsd wants to refer another xsd whose "targetNamespace" values is different.
The <include> tag has to be used, when the "targetNamespace" of the referred xsd is same as the "targetNamespace" of the referring xsd..
You cannot "import" an xsd whose "targetNamespace" is same as the "targeNamespace" of the referring xsd file...
Similarly, you cannot "include" an xsd whose "targetNamespace" is different from the "targetNamespace" of the referring xsd file.