This is the push in push vs pull
Is that also an Process - Inter Process Communication (IPC)
Documentation / Reference
wiki/Push_technology such as:
- Long polling: With long polling, the client requests information from the server exactly as in normal polling, but with the expectation the server may not respond immediately. If the server has no new information for the client when the poll is received, instead of sending an empty response, the server holds the request open and waits for response information to become available.