Which protocol is also called a push protocol?

Excuse me, could you elaborate on what you mean by a "push protocol"? Are you referring to a communication protocol that actively sends data to a receiving party without the need for an explicit request from that party? If so, could you provide an example of a specific protocol that falls under this category? Additionally, are there any notable characteristics or advantages that this type of protocol possesses that sets it apart from other types of protocols? I'm quite curious to learn more about this topic.