A softphone (software telephone) is an application program that enables voice over Internet Protocol (VoIP) telephone calls from computing devices. In the enterprise, softphones are sometimes referred to as soft clients. A softphone is a software program for making telephone calls over the Internet using a general purpose computer, rather than using dedicated hardware. The softphone can also be installed on a piece of equipment such as a workstation, portable computer, tablet or even a cellphone and allows the user to place and receive calls without requiring an actual telephone set. Often a softphone is designed to behave like a traditional telephone, sometimes appearing as an image of a phone, with a display panel and buttons with which the user can interact. A softphone is usually used with a headset connected to the sound card of the PC, or with a USB phone.