The  Microsoft Access (ADO) Connector is used to define a connection with a specific  database.

It is accessed through:

  Project > Add Layer > From Data Source... > Microsoft Access > 
or
  Tools >  Data Source Explorer... > Microsoft Access > 

To define Microsoft Access (*.mdb) database as a data source in your application,  fill the Title, the Connection Information Provider (is automatically filled) and File/URL with the path to the data source (*.mdb ) , and Password  when applicable.

As a example, the connection parameters to a database called "my_db" can be:

1. Title = conn_access_ado_my_db 
2. Description (optional) = this data base will store data from IBGE
   
3. Provider = Microsoft.Jet.OLEDB.4.0
4. File/URL =  C:/xxx/xxx/my_db.mdb  (or click on  )
5. Password =  ******* (optional)
6. Press Open to make this connection available at Data Source Selector with the same title specified here. 
7. Press Test to check the parameters used to establish the connection (optional).