1) Diff. b/w DataReader and DataSet? 2) What are the main five differences between Connected and Disconnected environment? 3) Difference between ADO and ADO.Net 4) Diff b/w DataSet vs DataTable 5) What is different between SqlCommand object and Command Behaviour Object? 6) Differences between oracle 9i and sql server? 7) Difference between Stored procedure and user defined functions? 8) What is the difference between oledbreader and dataset while connecting? 9) What's the difference between Dataset.Clone and Dataset.Copy? 10) What are the differences between RAW, AUTO and Explicit modes in retrieving data from SQL Server in XML format? 11) Difference between DataReader and DataAdapter / DataSet and DataAdapter? 12) Difference between OLEDB Provider and SqlClient?