First of all, we must clarify the following terms:
Agent: this is the name given to the "operators" working in your call center.
Database: is the xls or csv document with the data of the contacts you want to call.
Queues: The predictive dialing software sends the calls of the contacts who have picked up their phone to a "queue" of calls. This queue is responsible for assigning that call to an available agent. The predictive dialing software calculates the number of simultaneous calls to make so that all agents are busy for as long as possible and do not have to stand by while the system dials the call. Typically there is one queue per agent group.
Autodialer: each "autodialer" corresponds to a "campaign". Each "autodialer" is assigned to a queue.