VoIP

VoIP (Voice over Internet Protocol) is one of a family of internet technologies for delivery of voice communications over the Internet.

Internet telephony refers to communications services—voice, fax, SMS, and/or voice-messaging applications - that are transported via the Internet, rather than the public switched telephone network (PSTN).

There are three types of VoIP solutions that are commonly used; Proprietary  based systems such as Skype, standard based systems such as Draytel and Sipgate and PBX systems which use a SIP trunk.

The end user can make use of their PC together with microphone and speakers and appropriate software (which is usually free).