What is a Softphone?By:Robert Pepper (G+)
A softphone is software that allows the user to make telephone calls on a computer. Google Voice and Skype are popular softphones. Softphones have their own network, and typically calling one user within the network is free, but it costs a small amount to send or receive calls. Some VoIP providers, including residential provider Vonage, and enterprise provider 8x8, have softphone software as an add-on. Most enterprise VoIP providers offer an app that connects your smartphone to their network, rather than the phone's native carrier, essentially turning a phone into another kind of phone.
There are many ways to use a softphone the same way you would use a landline. You can buy a Skype phone, use a headset or microphone, or use a USB adapter as an ATD converter. There are also apps for tablets, including the iPod Touch, that allow you to use softphones over Wi-Fi. A softphone is good for residential users, and works well as a second line in a home.