Voice over IP is a new and popular technology that is used to make cheap international calls. VoIP calls can be placed between two computers or between a computer and a telephone. The call is established over the internet connection which is why it is called voice over internet protocol.
If you check the rates of any internet phone service provider you will notice that internet calls are in general much cheaper than international calls through calling cards and other methods. Why are internet calls cheaper than others?
VoIP calls convert the analogue signal of the voice from one end into a digital signal. This digital signal is then sent over the web connection to the destination device, whether it is a computer or a VoIP hand held device. The signal on reaching the destination is converted back into an audio signal.
While VoIP calls were only possible between two computers until recently, today, most Smartphones and other hand held devices are data enabled, which makes them able to make and receive VoIP calls. Many phones are compatible with specific VoIP applications such as Skype.
VoIP makes use of high speed internet technology and transfers lots of digital data over one line, making it a cost effective system for VoIP providers. While computer to computer calls are free, one needs to normally pay to call a normal phone from the computer.