The technology that enables real-time communication in messaging apps is mainly based on WebSocket protocols. WebSockets provide a persistent connection between the client and server, allowing bidirectional data exchange without the overhead of constantly reopening connections. This facilitates immediate message delivery and enhances user experience in services like WhatsApp and Slack. Other technologies like Firebase Cloud Messaging and Real-Time Messaging Protocol (RTMP) also play roles in enabling real-time interactions, ensuring that messages are delivered instantaneously, crucial for effective communication in diverse applications.