RabbitMQ is an open-source message-broker software that originally implemented the Advanced Message Queuing Protocol (AMQP) and has since been extended with a plug-in architecture to support Streaming Text Oriented Messaging Protocol, MQ Telemetry Transport, and other protocols.
message broker acts as a
middleman for various services (e.g. a web application, as in this example). They can be used to reduce loads and delivery times of web application servers by delegating tasks that would normally take up a lot of time or resources to a third party that has no other job.