VoiP, or voice over the internet protocol allows for the transmission of voice over the internet. This convention provides a way of making phone calls from your computer. VoiP is also commonly known as broadband phone service.
Perhaps the most well known free calling service, Skype Messenger is a freeware that allows users to make and receive voice calls from the internet. Skype allows for both one-on-one conversations as well as conference calls, with the additional option to video chat using your computer's webcam.
In addition to video chat capabilities, Skype is also capable of making phone calls to mobile phones or landlines. These services do come at an additional, albeit minimum, cost depending on which area of the world you would like to call. Being multi-language software, Skype is well known for its high-quality voice calls and for its friendly use.
PC-Telephone is a powerful software program designed to make calls via the internet to another computer or even via landlines. Making a call from computer to computer is free and making calls from computer to ordinary phone is cheaper than conventional telephone calls.