In a recent IoT, WebHooks, Zapier masterclass hosted by Ably, the concept of 'Realtime' was introduced and explained. Realtime applications involve event-driven communication where entities are interested in being notified as soon as something occurs. These apps require low latency communication which traditional HTTP based communication cannot provide. Realtime protocols such as WebSockets, MQTT, and SSE allow for push-based communication, enabling server-initiated communications. The masterclass covered the development of a realtime voting app using Ably's API to facilitate communication between two separate entities or apps. The app was built with HTML, bootstrap, Fusioncharts, and hosted on Glitch. The next episode in the masterclass series will focus on IoT, WebHooks, Zapier, and other related topics.