Please refer to the following URL to know the differences between Typed DataSet and Untyped DataSet,
http://onlydifferencefaqs.blogspot.in/2012/08/adonet-difference-faqs-2.html
Typed datasets are more self documenting and easier to work with at design time (overall). MyTypedDataSet.MyDoctor.FirstName = "Fred" vs. MyUntypedDataSet.Tables("Doctors").Row(0).Item(1)= "Fred"