There are many types of VOIP devices that are used to take calls from the home pc. These are very simple and easy to use and cost less. It is an exciting technology. The most common device however is the ATA which is the Telephone Adapter which is Analog mode.
The VOIP allows you to connect the telephone to the internet connection at home. This helps to convert the analog signals to the digital data which is transmittable. The ATA is a very easy to use and simple device. So all you have to do is to plug in the cord from the phone at your residence that would get connected to the wall jack and into the Analog Adapter (ATA). You are now ready to make calls to any place in the world.
The other type of VOIP device is the pc to pc device. Long distance calls can be made, without any charges. You have to only pay the monthly ISP fees and many companies would offer less priced softwares which you can install on the pc. You can talk to anyone in the world using this connection. You have to be equipped with speakers, microphone and also a sound card.
There are other types of devices that are coming up soon as there is a progress in technology each day.