first we look into the hierarchy of microsoft-provided data providers. we examin the connection objects
                           Idbconnection (the parent class)

1. sqlconnection
   
2. oracleconnection
3. accessconnection
4. oledbconnection

these are some derived classes used for establishing connection objects. but these are database specific classes. keeping this into mind we can infer that-
                         

• Database specific provider can instantiate specific connection to database
• these are optimized to perform fast as compared to parent classes they are derived from.
• the main disadvantage is that if we have hardcoded such specific providers in our application and there is a possibility of migrating to another database from the current we are using, we have to alter our data access layer.
• but applying design patterns such as factory method or abstract factory solves this problem.
• 
  

• 
  

ADO.Net is used mainly for disconnected data architecture. So it can handle applications from single tier to multi-tier. Even web applications will be compatible with ado.net. Migrating data from DBMS to RDBMS is quite easy in ado.net. Ensuring data security when travels from one end to another. The only disadvange is that we have to buy this tool from Microsoft.

This is a test answer

SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it’s a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.