A WebRTC client, in its most popular implementation, is an HTML webpage(s) that loads a JavaScript(s). Together, HTML and JavaScript define the GUI and the behavior of the WebRTC client.

Usually the JavaScript part, loaded by the HTML, leverages one or more JavaScript libraries. Those libraries implement the signaling protocol of choice (in our case SIP or VERTO) and its interaction with WebRTC APIs.
We have already seen how WebRTC APIs provide for accessing the local computer multimedia hardware (microphone and camera), manage the peer-to-peer streaming of audio and video with the peer, and a bidirectional data channel.

The session signaling protocol will leverage and complement those WebRTC P2P capabilities, so they become useful for much more than a connection to a pre-known address and port.