c#

They are base interfaces from which SqlAdapter/OldeDBAdapeter and SqlCOnnection/oledbCOnenction derives, and as per my knowlge there is nothing like IDataTable in .net

consider you have to write a generic method which can be used for bith Oledb and Sql at that time you cant use concrete classes like sqlconnection or oledbconnection.


Example:

public void getDataTable(string query,IConnection con){......}


Now you can call this function as
OledbCOnenction o=new OledbCOnnection("...");
SqlCOnnection s=new  SqlCOnnection ("..."); 
getDataTable("Select * from emp",o);
getDataTable("Select * from emp",s);

Hope you understood and it helped you, check this is correct answer if it does.