This document discusses WebRTC and how it enables real-time communications directly in web browsers without plugins. It provides an overview of WebRTC, including what it is, who is behind it, how it works using peer-to-peer connections, example use cases, and how developers can get started using the Phono SDK to add real-time calling and messaging capabilities to web and mobile apps. The Phono SDK is demonstrated as an open source JavaScript library for building real-time apps with WebRTC capabilities.