A voice API is a tool for software developers to make and receive phone calls programmatically. Behind the scenes, a voice API bridges the Public Switched Telephone Network (PSTN) and applications connected to the internet. By using a voice API, software developers can program voice calling into their applications without specialized telecommunications knowledge and hardware.
Using a voice API enables developers to build call logic that extends to users on any device, over any network, anywhere in the world. It also allows developers to add full VoIP functionality to apps to make and receive calls over the internet alone, without interfacing with the PSTN.
The Twilio Programmable Voice API gives developers programmatic control over their calls, with APIs built for a wide variety of uses from basic phone to phone calling, app to phone calling, Interactive Voice Response (IVR), conference calling, SIP interfacing, call recording, transcription, call tracking, and more.
Read more about the Twilio Programmable Voice API here.