basically ADO .Net is based on disconnected data
architectures unlike traditional vb 6. 

interactions with database is done through data command and
dataset is the new concept that is in memory representation
of data in xml format we can also work with xml data doc.
class to segregate their contents.

easy use of transactions and structured exception handling.

data pis persisted in XML Format.

ADO.NET offers several advantages over previous versions of 
ADO and over other data access components. These benefits 
fall into the following categories:

Interoperability

ADO.NET applications can take advantage of the flexibility 
and broad acceptance of XML. Because XML is the format for 
transmitting datasets across the network, any component 
that can read the XML format can process data. In fact, the 
receiving component need not be an ADO.NET component at 
all: The transmitting component can simply transmit the 
dataset to its destination without regard to how the 
receiving component is implemented. The destination 
component might be a Visual Studio application or any other 
application implemented with any tool whatsoever. The only 
requirement is that the receiving component be able to read 
XML. As an industry standard, XML was designed with exactly 
this kind of interoperability in mind.

Maintainability

In the life of a deployed system, modest changes are 
possible, but substantial, architectural changes are rarely 
attempted because they are so difficult. That is 
unfortunate, because in a natural course of events, such 
substantial changes can become necessary. For example, as a 
deployed application becomes popular with users, the 
increased performance load might require architectural 
changes. As the performance load on a deployed application 
server grows, system resources can become scarce and 
response time or throughput can suffer. Faced with this 
problem, software architects can choose to divide the 
server's business-logic processing and user-interface 
processing onto separate tiers on separate machines. In 
effect, the application server tier is replaced with two 
tiers, alleviating the shortage of system resources.

The problem is not designing a three-tiered application. 
Rather, it is increasing the number of tiers after an 
application is deployed. If the original application is 
implemented in ADO.NET using datasets, this transformation 
is made easier. Remember, when you replace a single tier 
with two tiers, you arrange for those two tiers to trade 
information. Because the tiers can transmit data through 
XML-formatted datasets, the communication is relatively 
easy.

Programmability

ADO.NET data components in Visual Studio encapsulate data 
access functionality in various ways that help you program 
more quickly and with fewer mistakes. For example, data 
commands abstract the task of building and executing SQL 
statements or stored procedures.

Similarly, ADO.NET data classes generated by the tools 
result in typed datasets. This in turn allows you to access 
data through typed programming. 


Performance
For disconnected applications, ADO.NET datasets offer 
performance advantages over ADO disconnected recordsets. 
When using COM marshalling to transmit a disconnected 
recordset among tiers, a significant processing cost can 
result from converting the values in the recordset to data 
types recognized by COM. In ADO.NET, such data-type 
conversion is not necessary. 

Scalability
Because the Web can vastly increase the demands on your 
data, scalability has become critical. Internet 
applications have a limitless supply of potential users. 
Although an application might serve a dozen users well, it 
might not serve hundreds —or hundreds of thousands — 
equally well. An application that consumes resources such 
as database locks and database connections will not serve 
high numbers of users well, because the user demand for 
those limited resources will eventually exceed their 
supply. 

ADO.NET accommodates scalability by encouraging programmers 
to conserve limited resources. Because any ADO.NET 
application employs disconnected access to data, it does 
not retain database locks or active database connections 
for long durations.