Communicating with different databases, using the same code written, Get know how can a single line of code can do things more than you expect

All Data Base

Continue with 7 different databases
The same code just change the settings of the application.

Data Mapping

Convert the data directly an objects                 
Without having to deal with DataReader or DataSet ..

Data validation

check out the objects and their properties automatically without using if

Data Protection

Encrypt and decrypt data to and from the
database without modifying anything in your code permanently