WebRTC, according to Wikipedia, is “an API definition drafted by the World Wide Web Consortium (W3C) that supports browser-to-browser applications for voice calling, video chat and P2P file sharing without the need of either internal or external plug-ins”.
It is a free, open project that provides browsers and mobile applications with Real-Time Communications (RTC) capabilities via simple APIs. The WebRTC components have been optimized to best serve this purpose. The WebRTC initiative is a project supported by Google, Mozilla and Opera, amongst others.
WebRTC has now implemented open standards for real-time, plugin-free video, audio and data communication.