In the healthcare space, there are companies that function as intermediaries that forward claims information from healthcare providers to insurance payers, also known as clearinghouses.
Likewise, if we want to exchange messages between two distributed software components, we need a mediator. This mediator is known as the message broker. It receives incoming messages from a sender and sends them to a receiver. This way the sender and receiver can be totally decoupled.
A message broker acts as an intermediary platform in communication between two applications.