WebSocket provides a full-duplex communication channel over a single, long-lived connection between a client and a server. Unlike the traditional HTTP request-response model, WebSocket allows for bidirectional communication, where both the client and the server can send and receive messages independently of each other.

How WebSocket Works Compared to HTTP Requests:

1. Connection Establishment:
   • HTTP: An HTTP connection is established via a client sending a request to the server, and the server responding back. This process typically involves setting up a TCP connection for each request-response cycle, which is then closed after the response is received.
   • WebSocket: A WebSocket connection starts as an HTTP request (using the HTTP GET method with an Upgrade header), which is upgraded to a WebSocket connection if the server supports it. This upgrade changes the protocol from HTTP to WebSocket, allowing for continuous communication over the same TCP connection.
2. Communication:
   • HTTP: Communication is unidirectional and follows a request-response pattern. The client sends a request, and the server responds. Each communication cycle is independent, and a new connection is typically established for each request.
   • WebSocket: Communication is bidirectional. Once the connection is established, both the client and the server can send messages to each other independently and continuously without needing to re-establish the connection.
3. Message Exchange:
   • HTTP: Data is exchanged in the form of request and response messages, which include headers and optional bodies. Each message is separate and complete in itself.
   • WebSocket: Data is exchanged in the form of frames. Messages can be sent as text or binary frames, and multiple frames can be used to send a single message. This allows for more efficient communication, especially for real-time data exchange.
4. Use Cases:
   • HTTP: Suitable for scenarios where requests are infrequent and where the client typically initiates the interaction, such as loading web pages, submitting forms, or accessing APIs.
   • WebSocket: Ideal for real-time applications where constant communication is required, such as chat applications, live sports updates, financial tickers, online gaming, and collaborative platforms.
5. Performance:
   • HTTP: Each request-response cycle can introduce latency due to the overhead of setting up and tearing down connections and the stateless nature of HTTP.
   • WebSocket: Reduces latency by maintaining a persistent connection, allowing for faster and more efficient data transfer, especially for applications requiring low-latency communication.

WebSocket Example Workflow:

1. Handshake:
   • The client initiates a WebSocket connection by sending an HTTP request with an Upgrade header to the server.
   • If the server supports WebSocket, it responds with a 101 Switching Protocols status code and completes the handshake, upgrading the connection to WebSocket.
2. Communication:
   • Both the client and server can now send and receive messages independently. The connection remains open, allowing for continuous data exchange.
3. Closing the Connection:
   • Either the client or the server can close the WebSocket connection by sending a close frame. The connection is then terminated, and any associated resources are released.

In summary, while HTTP requests are suitable for traditional client-server interactions with infrequent and stateless communication, WebSocket excel in scenarios requiring persistent, real-time, and bidirectional communication.