PubNub and Socket.IO are distinct yet complementary technologies, with Socket.IO serving as a framework for establishing robust bidirectional network communication and PubNub providing a globally distributed data stream network for fast, secure data delivery. While Socket.IO facilitates real-time features through socket connections, it requires developers to manage their server infrastructure. PubNub simplifies this by eliminating the need for a server backend, offering additional real-time functionalities such as presence detection, message persistence, analytics, and cross-platform data encryption and serialization. This integration allows applications to scale efficiently to accommodate growing user bases without the complexities of backend management, leveraging PubNub's infrastructure to handle real-time protocols and frameworks. The PubNub Socket.IO SDK aids developers transitioning from a Socket.IO-based application to PubNub, ensuring ease of use and scalability for real-time applications.