Describe several methods of communication between the server and the client.

HTTP Requests (REST API): The most common method. The client sends requests (GET, POST, PUT, DELETE, etc.) to specific server URLs to retrieve or send data. The server responds using standard HTTP status codes and data formats (often JSON).

WebSockets: Provide a persistent, bidirectional connection between the client and server. They allow the server to send data to the client at any time without the client having to request it. Ideal for real-time applications (chats, online games, notifications).

Server-Sent Events (SSE): One-way connection from the server to the client. The server can send data streams to the client as they become available. Suitable for receiving real-time updates from the server (e.g., stock quotes, sports scores).

GraphQL: An alternative to REST API. Allows the client to request only the data it needs from a single access point on the server. Increases query efficiency and reduces data redundancy.

WebRTC: Technology for direct peer-to-peer (p2p) connections between browsers. Used for data exchange, voice, and video communication without an intermediary server (after establishing the connection).

Polling: The client periodically sends requests to the server to check for new data. Less efficient than WebSockets for frequent updates, as it creates additional load on the server and network.

Long Polling: The client sends a request to the server, and the server keeps the connection open until new data appears or the timeout expires. More efficient than regular polling but still less effective than WebSockets in terms of efficiency and latency.