in a simple term or lay mans language Ado.net is just the integration of your Database with your project which you develop in either vb.net or C#. i.e integrating your sqlserver to your visual studio project.

ADO.NET is stateless mechanism. I can treat the ADO.Net as a separate in-memory database where in I can use relationships between the tables and select insert and updates to the database. I can update the actual database as a batch