Predictive dialing
Calling more numbers than you have free agents, on the bet that most will not be answered, so an agent is talking again the moment the last call ends.
On the floor
It is the fastest of the four modes and the only one that can get you in trouble, because the bet is sometimes wrong and someone answers with nobody there. Progressive dials one number per free agent, preview shows the agent the record before it dials, and manual is click to call. Most floors run predictive for cold lists and preview for anything that needs preparation.
The four dial modes