As sb8244 explained, long-polling typically refers to the server waiting before responding, and then responding with a complete response in one shot. What you'

As sb8244 explained, long-polling typically refers to the server waiting before responding, and then responding with a complete response in one shot. What you're thinking of, an HTTP response that the server keeps appending to and the client is expected to read and process incrementally, is also a real thing though. This is typically referred to as HTTP streaming. Examples of this would be SSE (text events) or MP3 streaming (audio). (Not to be confused with HTTP Live Streaming (HLS) which is typically not based on any long lived requests at all!)