Explain connection string in test complete in detail

on the link below:

https://support.smartbear.com/testcomplete/docs/testing-with/advanced/working-with-external-data-sources/databases/using-ado-and-bde-objects/working-with-ado-command-object.html


in the line

 AConnection.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + _
  "Data Source=C:\Microsoft Visual Studio\VB98\biblio.mdb"

What is provider how can i find it or it's just a connection string Syntax ??

And  in the line

 Cmd.CommandText = "Select * From Authors WHERE Authors.[Year Born] < :MyParam"
  Cmd.CommandType = adCmdText

What is MyParam ?
what is the mean CommandType and adCmdText ?
Can we execute as many query as we need ?