Sockets, a longstanding networking paradigm, facilitate data exchange across different hardware through standardized input and output, akin to APIs. WebSockets extend this concept, overcoming HTTP's limitations by maintaining open connections for real-time data transfer, unlike HTTP's resource-intensive opening and closing of connections. REST, another abstraction, structures APIs using predictable HTTP operations but is less efficient for real-time interactions due to its polling method. While REST is suited for applications with infrequent user interaction, WebSockets excel in real-time communication by allowing servers to push updates directly to clients. The metaphor of a general and soldiers illustrates how WebSockets streamline communication, reducing server burden and enhancing client efficiency. PubNub leverages WebSockets for scalability and reliability, providing a more cost-effective solution compared to setting up and managing frameworks like Socket.IO, which require significant resources and can incur downtime costs during operational challenges.