DTD Vs Schema

Hello all,

Just for the sake of more knowledge, though I know little bit about it
myself, but curious to have some experts comments. 

1. What is the main difference between a DTD and Schema?
2. How do they differently define a structure/data type of an XML elements
or attributes?
3. Though I work on DTDs a lot but I like the Schema Syntaxes like:

			<xs:sequence>
				<xs:element name="ABC" minOccurs="0"
maxOccurs="unbounded">
					<xs:complexType>
						<xs:simpleContent> 


4. Personally I don't see any limitations in DTD,then why it was required to
introduce Schema in scenario?
5. How should one can decide it should go for Schema and not DTD or
vice-versa depending upon the data, which needs to be structured?

I may be asking very childish questions, may be because these days I am
working on different projects which follows Schemas (one of them is to
transform different XMLs, following different DTD into XML following a
Schema), but belive me I basically do not found any major difference.

I have lots of questions coming into my mind right now ......... For which I
know answers partially but would prefer listen experts. If somebody feels to
answer them, that will be appreciated otherwise please do not get bothered.


Best,

Pankaj Chaturvedi

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