Voice

You use Voice to integrate text-to-speech into your workflow and build interactive voice response systems.

Voice API

Build fully featured voice applications such as recorded voice proxies, voice conferencing systems, lead distribution and customer support systems. With Voice API you initiate and control Calls to and from the PSTN.

SIP

Forward inbound and send outbound Voice calls that use the Session Initiation Protocol

Note: you can find the docs for deprecated Voice products in Deprecated Voice products.