WebRTC lets us make calls right from a web page without any plugin. This was made possible using media APIs of the browser to fetch user media, WebSocket for transportation, and HTML5 to render the media on the web page. Thus, WebRTC is an evolved form of WebSocket communication. WebSocket is a Transport Layer protocol that carries data. The WebSocket API is an Application Programming Interface (API) that enables web pages to use the WebSocket protocol for (duplex) communication with a remote host.

In this chapter, we will study how WebRTC really works. We will also demonstrate the use of WebRTC media APIs to capture and render input from a user's microphone and camera onto a web page. In the later part of chapter, we will find out how to build a simple standalone WebRTC client using the plain WebSocket protocol as the signaling mechanism.