A call center is a group or department in which employees receive and make high volumes of telephone calls. Call centers can have internal customers (e.g., help desks) or external customers (e.g., customer service and support centers). The call center uses a variety of technologies to improve the management and servicing of the call. A center that use both phone- and non-phone-based communication channels (e.g., e-mail or the Web) is known as a contact center.