What is a softphone?
Softphones are like virtual phones: they are software programs that allow you to make voice-over internet protocol (VoIP) calls over the Internet. This software can be installed on a PC, laptop, or mobile device. You can talk through a pair of headphones or from speaker phone on whatever device you have on hand. The user interface looks like a phone screen on a mobile phone, including controls like starting and ending the call and accessing the contacts list.
There are several programs that provide users with virtual phones: