Question - What do you understand by DataRelation class? 
          
        
        Answer - 
        
The DataRelation is a class of disconnected architecture in the .NET framework. It is found in the System.Data namespace. It represents a relationship between database tables and correlates tables on the basis of matching column.
- DataRelation drel;
- drel = new DataRelation("All", ds.Tables[0].Columns[0], ds.Tables[1].Columns[0]);