RESTXML documents comprise of Plivo Elements. There are 10 core Plivo Elements:
<Speak>: Read some text to the caller.
<Play>: Play an audio file to the caller.
<Record>: Record a call or part of a call.
<GetDigits>: Get the digits a caller presses.
<Dial>: Call another phone number or conference and connect the current caller.
<Conference>: Create and join a dynamic conference.
<Hangup>: Hang up the call.
<PreAnswer>: Answers the call in early media mode. Useful for playing custom caller tunes.
<Redirect>: Redirects the call flow to a new URL to receive RESTXML
<SIPTransfer>: Reroutes a SIP call to a SIP URI.
<Wait>: Wait for a specified time before executing the next element.