The technology essential for enabling instant messaging applications is the use of WebSocket protocol. This technology establishes a persistent connection between clients and servers, allowing for real-time, two-way communication. Unlike traditional HTTP requests, WebSockets enable continuous data exchange without the overhead of re-establishing connections, facilitating low-latency communication. This capability is crucial for instant messaging, enabling features such as notifications, message delivery statuses, and group chats, enhancing the overall user experience in messaging platforms.