Who specifically initiated the data transfer via WebSocket in the project?

In a project using WebSocket, data transmission is usually initiated by the server-side — a Node.js application. The server opens a WebSocket connection and sends data to clients as needed.

However, the initiator of the transmission can also be the client, which sends requests or messages via WebSocket, and the server processes them and responds.

Thus, the start of data transmission via WebSocket depends on the architecture:

• If the server pushes updates — the server initiates the transmission.
• If the client requests data — the client initiates the transmission.

In most cases, it is the server that is responsible for sending data via WebSocket, maintaining a persistent connection with clients.