ADO object model includes five components.
They are:
SqlConnection Object,SqlCommand Object,SqlDataReader 
object,Dataset object,SqlDataAdapter object.

Not Sql ADO Object Model Only.But ADO.Net has the following 
methods also

1.OLEDBProvider
2.SQLProvider
3.ODBCProvider

the above all has the Connection,Command,Data Reader, Data 
Set, Data Adapter Also.So Finally List Only Common Object 
Models , They are

 1. Connection Objects
 2. Command Objects
 3. DataReader Object
 4. DataSet Object
 5. DataAdapter Object

The main object model of an ADO.Net architecture is "Data 
Provider". It provides data access to SQl server ,Oracle, 
Access in order to retreive,update and insert data in the 
datastore.

the main objects of ADO.Net object model are....

1.connection object : used to establish connection to 
database.

2.command object: it is used to execute commands and stored 
procedures.

3.dataAdapter object: used to establish connection between 
datastore and dataset.

4.dataReader object: used to read data from dataset in 
forward only.