A virtual classroom is a synchronous online environment that reproduces the key mechanics of a physical classroom: a host-instructor who controls the session, learners who can speak or type, and shared artefacts like slides, a whiteboard, and a screen-share feed. Unlike a generic video call, a virtual classroom platform enforces pedagogical roles — the instructor admits participants, mutes or spotlights individuals, and splits the group into breakout rooms for small-group tasks. Real-time audio and video are typically delivered over WebRTC, which keeps latency low enough for natural turn-taking. The shared whiteboard gives the instructor and learners a persistent canvas to annotate together, while hand-raising provides a lightweight signal channel that avoids the chaos of everyone unmuting at once. Session recording captures the full event — video, audio, whiteboard state, and chat — for asynchronous replay, and post-processing workflows trim and chapter that recording into the on-demand catalog. Engagement features like polls, in-session quizzes, and reaction emoji are increasingly standard and generate xAPI signals that feed learning analytics. The main engineering challenges are NAT traversal for participants behind firewalls, media routing at scale via an SFU, and state synchronization so the whiteboard remains consistent across hundreds of concurrent connections.
