WebRTC, a free and open-source project, is widely adopted by top companies for creating real-time communications (RTC) in browsers and mobile devices, allowing for seamless streaming of video, audio, and data. The blog post details the process of building a video chat application using WebRTC, which enables users to watch YouTube videos together. It highlights the importance of a signaling service, like PubNub, to coordinate communication by sending metadata between callers before a connection is established. The application employs WebRTC's PeerConnection API for direct peer-to-peer connections and uses DataChannels to stream messages. The tutorial also covers browser compatibility, testing, debugging, and the integration of necessary libraries such as jQuery and the PubNub JavaScript SDK. Additionally, it explains how to manage calls, synchronize video playback through the YouTube API and DataChannels, and enhance WebRTC applications using PubNub's features for live chats and real-time video recommendations. For production-quality connections, it advises using XirSys for STUN and TURN servers to handle connectivity issues in real-world scenarios.