Is call to center are the centers of concentration of the telephone calls of the clients who need attendance. The technology used in call to center includes the infrastructure of telephone switchboard, phonecards and middleware-CTI. In the past the center of a center of calls it was the telephone interchange with an adjacent ACD, that is hardware and software necessary to assign the incoming calls with the aim of distributing the load between all the operators for a certain service. Today the heart of call to center is the network of company LAN (Local Area Network) or WAN (Wide Area Network) and the software of CTI for the control of the system. Thus, the change becomes the device of network with the function of management of the connection of input/output with public the wire net.

The contact center is different from call to center classic because that is characterized by the management of the different channels from contact with the clients. A Center of Contact provides the service of support to the clients through telephone calls, but also through other mass media as they can be, for example, fax or email. Both are aprte than technically Sevicedesk is called.