A conversation that stays open
A web request is often like asking a question and getting one answer. A WebSocket is more like a phone call: once connected, both sides can send messages without starting over each time.
That helps chats, games, and shared documents show changes quickly.
When the connection breaks
If the connection drops when a device sleeps or loses its network, the app must reconnect and may need to catch up on missed updates. Keeping many connections open also takes work for the server, so WebSockets are most useful when updates need to flow both ways.