WebSockets allow for real-time communication between clients and servers by establishing a persistent connection. Unlike the traditional HTTP request-response model, where clients initiate requests and servers respond, WebSockets let servers send data to clients without needing a request each time. The connection begins with an HTTP/1.1 handshake, where the client sends a request with specific headers indicating the desire to upgrade to a WebSocket connection. If the server supports WebSockets, it responds with a status code indicating the switch has been made. This process involves a unique key exchange to ensure a secure handshake. WebSockets are particularly useful for applications needing real-time data exchange, such as online chat, multiplayer gaming, and live updates. They eliminate the inefficiencies of polling, where clients repeatedly ask for updates. However, WebSockets have drawbacks. They can encounter issues with proxies that aren't designed for persistent connections, and their stateful nature makes horizontal scaling more complex. In scenarios where only server-to-client communication is needed, simpler alternatives like EventSource may be more efficient. EventSource allows the server to push updates over a single HTTP connection without the overhead of a full-duplex WebSocket connection. For applications that require straightforward request and response interactions, using WebSockets may not be necessary. Understanding these factors helps developers choose the right technology for their specific use cases.