A call center is a platform combining workstations or "positions" occupied by teleoperator or telemarketer. These platforms goal are achieve telemarketing campaigns wether it is by inbound or outbound calls.
The current trend is to do not talk about call centers anymore but contact centers which will have as a goal to integrate all the contact channels with the client other than the telephone.
On e-prospects many of the providers are call centers inshore and/or offshore with different methodologies but always with the better standards if they want to stay on the platform.