Can you explain how the WebSocket protocol works and how it differs from regular HTTP requests?

WebSocket is a protocol that provides a full-duplex (two-way) persistent connection between a client and a server over a single TCP connection. Unlike regular HTTP requests, which are unidirectional and short-lived (client sends a request, server responds, connection closes), WebSocket establishes a persistent connection, allowing both parties to exchange data at any time without reopening the connection.

Working mechanism:

1. The client initiates a connection to the server via an HTTP request with the header Upgrade: websocket.
2. If the server supports WebSocket, it responds with a confirmation and the connection is "upgraded" from HTTP to WebSocket.
3. After establishing the connection, the client and server can exchange messages in real time.

This is especially useful for applications with high interactivity, such as chats, games, and stock trading terminals.

Example of difference:

• HTTP: the client sends a request, the server responds, and the connection closes.
• WebSocket: the connection remains open constantly, and message exchange occurs in both directions without repeated requests.