In ADO.NET and ADO there are lot of similarities but there are few differences which needs to be taken care of.In ADO.net there is a Dataset Object instead of recordset object in ADO.

ADO works with connected data while ADO.NET uses data in disconnected fashion that is good for performance because you need not to keep connection active all the time. ADO.NET needs open connection only to get the data from tables or to make an updation to data.Thus a DataSet is a separate entity from the database. You can fill your dataset manually without using a data source.

In ADO recordset is a representation of table it does not contain information regarding constraints and keys.Dataset in ADO.NET contains all this information.

The recordset object in ADO provides a single table view of data although we can use various kinds of joins in order to get data from different tables to create a new set of records.Dataset Object in ADO.net is able to contain more than one
table of data at a time. which makes it much more functional than the Recordset object.

Dataset in ADO.NET allows you to manipulate data using XML.You can get data from your tables in dataset and then can write this data to a xml file and vice versa you can get data in dataset from XML file and then insert it into a atabase.This is really good thing because it allows you to communicate with other applications which passes data in XML.